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THE 


CLASS-BOOK  OF  ANATOMY, 

DESIGNED  FOR  SCHOOLS, 

EXPLANATORY  OF  THE 


FIRST  PRIN  CIPLES 


HUMAN  MECHANISM 

AS  THE  BASIS  OF 

PHYSICAL  EDUCATION. 


BY  JEROME  V.  C.  SMITH,  M.  D. 


“ for  I am  fearfully  and  wonderfully  made  : ” 


BOSTON: 
ALLEN  AND  TICKNOR. 
1834. 


5wu  tfi- 


Entered  according  to  Act  of  Congress,  in  the  year  1834, 

By  Allen  and  Ticknor, 

in  the  Clerk’s  Office  of  the  District  Court  of  Massachusetts, 


PREFACE. 


The  object  of  the  following  pages  will  be  readily  un- 
derstood ; and  should  the  work,  in  the  hands  of  public 
instructors,  be  instrumental  in  explaining  to  the  young, 
for  whom  it  was  designed,  a general  knowledge  of  their 
own  curious  organization,  it  may  lead  to  the  adoption  of 
such  habits  in  early  life  as  will  insure  health  in  youth, 
and  intellectual  vifror  in  aste. 

O O 

The  questions  interspersed  through  the  book  are  far 
from  embracing  all  the  subjects  adverted  to  in  the  sev- 
eral natural  divisions  of  the  text : — they  are  merely  ex- 
amples of  the  best  mode  of  conducting  the  study,  leav- 
ing it  entirely  with  the  teacher  to  select  such  parts  for 
recitation  as  he  may  conceive  most  advisable. 

Technical  words  have  not  been  wholly  avoided  ; — 
such  as  have  been  retained,  are  for  the  master,  and  not 
for  the  pupil,  to  aid  him  in  acquiring  a more  minute  and 


VI 


PREFACE. 


exact  knowledge  of  the  science,  that  he  may  be  the  bet- 
ter prepared  to  assist  those  who  are  intrusted  to  his  care. 

Should  the  volume  meet  the  approbation  of  those 
who  are  devoted  to  the  best  interests  of  mankind,  it  will 
not  have  been  written  in  vain. 

J.  V.  C.  Smith. 

Quarantine  Ground,  ) 

Port  of  Boston.  J 


Jan.  1834. 


CONTENTS. 


Page. 

The  Bones,  — Osteology,  ....  2 

The  Ligaments,  — Syndesmology,  ...  45 

The  Muscles,  — Myology,  ....  50 

Apparatus  of  Joints,  — Bursology,  . • • H4 

Fluids,  — Angiology,  .....  115 

The  Nerves,  — Neurology,  .....  153 

The  Senses,  .......  1?5 

The  Ear,  ...••••• 

The  Ete,  .......  205 

Feeling,  or  Touch, 240 

Smelling,  ......  - 240 

Tasting,  . . • • • • 241 

The  Glands,  — Adenology,  ....  242 

The  Viscera,  — Splanchnology,  ....  258 

The  Fluids, — Hygrology,  .....  269 

The  Skin,  .......  272 

j 


' W( 

■ 

.•  • , • 


ANATOMICAL  CLASS  BOOK. 


Anatomy  is  a useful  science,  which  explains  the  nature, 
office,  and  structure  of  every  part  of  the  human  body. 

From  remote  antiquity,  men  of  learning  and  persevering 
industry  have  labored  to  comprehend  and  explain  the 
complicated  machinery  of  man,  but  at  no  period  has  the 
subject  been  better  understood  than  at  the  present.  By 
the  study  of  this  science,  the  condition  of  the  species  has 
been  ameliorated  ; extreme  sufferings  have  been  avoided  ; 
and  in  the  aggregate,  human  life  has  been  prolonged. 

On  the  minds  of  youth  the  influence  exerted  by  a con- 
templation of  their  own  physical  condition,  founded  on  a 
general  knowledge  of  the  situation  and  functions  of  the 
different  organs,  must  certainly  have  a beneficial  tendency. 
As  they  discover  the  exact  regularity  of  parts  ; the  beauty 
and  harmony  resulting  from  particular  combinations  of 
machinery,  endowed  with  a high  degree  of  vitality,  on  the 
action  of  which,  health,  life,  and  happiness,  are  constantly 
depending,  surely,  it  would  be  strange  indeed  if  they  did 
not  fall,  in  humble  adoration  before  that  Supreme  Intelli- 
gence which  created,  and  which  sustains  them  in  ex- 
istence. 


1 


2 


ANATOMICAL  CLASS  BOOK. 


Comparative  anatomy,  implies  a dissection  of  the  infe- 
rior animals,  as  birds,  fishes,  reptiles  and  even  plants,  in 
order  to  demonstrate,  analogically,  the  functions  of  similar 
apparatus  in  man.  This  is  an  exceedingly  useful  pursuit, 
and  though  philosophers  have  apparently  been  guilty  of 
unnecessary  cruelties,  it  was  not  from  a desire  of  gratify- 
ing a malevolent  disposition ; — on  the  contrary,  all  their 
researches  have  had  reference  to  relieving  mankind  from 
some  of  those  manifold  evils,  to  which  the  splendid  me- 
chanical organization  of  the  frame  is  predisposed. 


ANATOMY  IS  DIVIDED  INTO  NINE  PARTS. 


Os-te-ol-o-gy,  which  treats 
Syn-des-mol-o-gy,  “ 
My-ol-ogy. 

Bur-sal-o-gy, 

Ati-gi-ol-o-gy , 

A-den-ol-o-gy, 
Splaneh-nol-o-gy, 

Hyg-rol-o-gy, 


of  the  bones. 

“ ligaments. 

“ muscles. 

“ apparatus  of  joints, 

of  vessels,  as  veins  and  arteries, 
of  the  glands. 

“ viscera,  as  the  stomach,  &c. 
“ fluids,  as  the  blood,  bile  &c. 


OSTEOLOGY. 

All  the  bones,  in  manhood,  are  hard,  and  almost  insen- 
sible, being  composed  of  earth  and  lime,  held  together  by 
means  of  gelatin,  a kind  of  glue,  secreted  by  appropriate 
vessels.  The  substance  of  the  long  bones,  as,  for  exam- 
ple, those  of  the  limbs,  are  compact,  excepting  at  their 
extremities,  where  they  become  irregularly  larger,  and 
slightly  spongy.  They  are  classed  in  the  following  man- 
ner : — 

r 1.  Cylindrical,  — bones,  as  in  the  arms. 

<2.  Flat,  — bones,  as  in  the  shoulder  blades. 

(.  3.  Irregular,  — bones,  as  the  ribs  and  those  of  the  skull. 


ANATOMICAL  CLASS  BOOK. 


3 


THEY  ARE  FURTHER  SUBDIVIDED  INTO, 

First,  — hollow  bones,  possessing  marrow. 

Second,  — flat  bones,  or  those  destitute  of  marrow. 

Before  arriving  at  about  the  age  of  twenty,  the  ends  of 
the  bones  are  considerably  spongy,  and  imperfectly  united 
to  the  main  shaft,  — and,  therefore,  termed  epiphises,  from 
two  Greek  words,  meaning  to  grow  upon,  but  afterwards, 
they  become  firmly  united. 

The  names  of  a majority  of  the  bones  are  very  arbitrary  ; 
some  of  them,  however,  have  their  appellation  from  a fan- 
cied resemblance  to  some  object ; others,  are  named  from 
their  shape,  connexion,  or  supposed,  or  real  use. 

Every  cavity,  hole,  or  prominence,  even  to  the  burden 
of  the  science,  has  also  a name,  — a knowledge  of  which 
is  a key  to  the  parts,  either  directly  in  contact,  or  lying  in 
the  immediate  vicinity. 

Protuberances  are  termed  processes,  and  are  generally 
the  points  of  attachment  for  muscles  or  ligaments; — the 
first  being  the  moving  power,  and  the  latter,  the  bands 
which  keep  the  ends  of  any  two  bones  in  juxtaposition. 

A natural  skeleton  is  one,  the  bones  of  which  are  held 
together  by  the  original  ligaments.  Remarkable  speci- 
mens of  these  kinds  of  preparations  are  common  in  mu- 
seums, and  cabinets  of  curiosities. 

An  artificial  skeleton,  is  one,  the  individual  bones  of 
which  are  united  together  by  wires. 

In  the  human  skeleton,  there  are  two  hundred  and  fifty- 
two  separate  bones.  Those  who  labor  hard,  have  some- 
times an  extra  number,  which  form  near  the  joints  of  the 
thumb,  fore  finger,  and  toes.  They  are  called  sesamoids, 
from  their  resemblance  to  the  seed  of  the  Sesamum  plant. 
They  are  useful  in  increasing  the  power  of  the  muscles 
wherever  they  grow. 


Dentes 


4 


ANATOMICAL  CLASS  BOOK. 


THE  SKELETON  IS  DIVIDED  INTO 

First,  — the  head. 

Second,  — the  trunk. 

Third,  — the  extremities. 


FIRST  DIVISION. 

There  are  fifty-five  bones  entering  into  the  composition 
of  the  head,  by  including  thirty-two  teeth. 

EIGHT  BONES  IN  THE  SICULL. 

One  os  frontis, — above  the  eyes,  constituting  the  forehead. 

Two  ossa  parietaiia,  — making  the  sides,  above  the  ears. 

Two  ossa  temporum,  — or  temple  bones. 

One  os  ethmoides, — or  sieve-like  bone,  lying  between  the  brain 
and  root  of  the  nose. 

One  os  sphenoides,  — being  the  bottom  of  the  skull,  nearly 
concealed. 

One  os  oceipitis,  — at  the  lower  and  back  part  of  the  head. 

FOURTEEN  BONES  IN  THE  FACE. 

Two  ossa  maxillaria  superiora, — the  two  making  the  upper  jaw. 
Two  ossa  malaruin,  — or  prominent  cheek  bones. 

Two  ossa  nasi,  — one  each  side,  making  the  arch  of  the  nose. 

Two  ossa  lachrymalia,  — just  within  the  angle  of  the  orbit  of 
the  eye. 

Two  ossa  palatina,  — in  the  back  part  of  the  roof  of  the  mouth. 
Two  ossa  turbinata, — within  the  nostrils. 

One  os  vomer,  — the  partition  in  the  centre  of  the  nose. 

One  os  maxillare  inferius, — the  under  jaw. 

THIRTY-TWO  TEETH. 

Eight  incissores, — front,  or  cutting  teeth ; — four  in  each  jaw. 

Four  cuspidate?,  — eye  teeth,  two  above  and  two  below. 
Eightbicuspides, — or  small  double  teeth,  with  two  cutting  points. 
Eight  molares, — grinding  teeth. 

Four  sapienti®,  — wisdom  teeth. 


ANATOMICAL  CLASS  BOOK. 


5 


IN  THE  TONGUE. 

One  os  hyoides, — shaped  like  a capital  U,  and  situated  at  the  under 
and  back  surface  of  the  under  jaw,  and  above  the  protuberance 
of  the  throat. 

Four  concealed  bones  of  the  ear,  collectively  termed, 
ossicula  auditus. 

Two  mallei,  malleus,  — faintly  resembling  a mallet. 

Two  incudes,  incus,  — or  the  anvil  shaped  bone  of  the  ear. 

Two  stapedes,  stapes,  or  stirup,  — almost  a fac  simile  of  the  stirup 
of  a saddle. 

T wo  orbicularia,  — or  round  bones,  but  considerably  smaller  than 
a mustard  seed,  and  the  smallest  bones  of  the  skeleton. 

SECOND  DIVISION. 

FIFTY-FOUR  BONES  OF  THE  TRUNK. 

The  spine,  or  back  bone,  is  constructed  of  twenty-four 
blocks,  called  vertebrae,  — of  which  there  are 
f Seven  cervical  vertebras,  — or  joints  in  the  neck. 

1 Twelve  dorsal  vertebrae, — or  joints  in  the  back. 

J Five  lumbar  vertebrae,  — being  larger  joints,"  in  the  loins  or 
f small  of  the  back. 

TWENTY-FIVE  BONES  IN  THE  CHEST,  OR  THORAX. 

One  sternum,  — or  breast  bone. 

Twenty-four  costae,  — or  ribs,  the  seven  uppermost  are  the  true, 
and  the  five  lowest,  false,  or  floating. 

FIVE  BONES  OF  THE  PELVIS. 

Two  ossa  innominate,  — or  nameless,  being  the  broad  hip  bones. 
One  os  sacrum,  — being  the  foundation  on  which  the  spinal 
column  rests,  of  a pyramidical  figure,  with  its  base  upward. 
Two  ossa  coccygis,  — the  extreme  lowest  point  of  the  sacrum. 

SIXTY-FOUR  BONES  OF  THE  UPPER  EXTREMITIES. 

In  the  C Two  claviculce,  — collar  bones, 
shoulders  ( Two  scapula,  — shoulder  blades. 

1* 


ANATOMICAL  CLASS  BOOK. 


In  the  arms,  two  ossa  humeri,  — between  the  shoulder  and  elbow. 
In  the  ( Two  ulna,  — on  the  under  side  of  the  fore  arm. 
fore  arm,  ( Two  radii,  — on  the  upper  edge. 


the  hand  is  divided  into 
The  carpus,  — or  wrist. 

The  metacarpus,  — palm  of  the  hand. 

The  phalanges,  — bones  of  the  fingers. 

Os  naviculare,—  boat  shaped  bone,  2 

Os  lunare,  — moon  shaped  bone.  2 

Os  cuneiforme,  — wedge  shaped  bone.  2 

Os  orbiculare, — round,  or  nearly  so,  bene.  2 

Os  trapezium,  — a geometrical  figure.  2 

Os  trapezoides,  — resembling  the  last  bone.  2 

l Os  magnum,  — so  called  because  the  largest.  2 

' Os  unciforme,  — being  hooked.  2 

Ossa  metacarpi, — ten  metacarpal  bones,  or  roots  of  the  fingers 
constituting  the  palms.  Five  in  each  hand. 

In  the  fingers  — twenty-eight  phalanges,  — finger  bones. 


Ossa  carpi,  or 
wrist  bones, 
eight  in  each 
wrist. 


SIXTY  BONES  OF  THE  INFER10H  EXTREMITIES. 

In  the  thighs,  two  ossa  femoris,  — thigh  bones. 

In  the  leg,  two  patella,  — knee  pans. 

two  fibula, — outside  bones  of  the  leg. 
two  tibia,  — or  shin  bones. 


THE  FOOT  IS  DIVIDED  INTO 
First,  — tarsus,  — or  instep. 

Second,  — metatarsus, — foundation  bones  of  the  toes. 
Third,  — phalanges,  — the  bones  of  the  toes. 

Os  calcis,  — heel  bone. 

Os  astro  galas,  — making  part  of  the  ankle  joint. 
Os  cuboides,  — square  bone. 

Os  naviculare,  — boat  shaped  bone. 

Ossa  cuneiformia,  — wedge  shaped. 

Ossa  metatarsi,  — five  bones,  foundation  of  the  toes. 

In  the  toes  of  each  foot,  fourteen  bones,  or  phalanges, — 
Eight  bones,  the  sesamoidts,  in  the  thumbs  and 
great  toes,  though  not  always  constant.  Total. 


Ossa  tarsi 
or  instep. 


2 

2 

2 

2 

6 

10 

28 

25  2 


ANATOMICAL  CLASS  BOOK. 


7 


Fig.  1. 


A front  view  of  the  male 
skeleton. 

HEAD  AND  NECK. 

а.  The  frontal  bone. 

б,  The  parietal  bone. 

c,  The  temporal  bone, 

d,  A portion  of  the  sphenoid 

bone. 

e,  The  nasal  bone. 

f The  malar,  or  cheek  bones. 

g,  The  superior  maxillary,  or 

upper  jaw. 

h,  The  lower  jaw. 

i,  The  bones  of  the  neck. 

TRUNK. 

a,  The  twelve  bones  of  the 

back. 

b,  The  five  bones  of  the  loins. 

c, d,  The  breast  bone. 
e,f,  The  seven  true  ribs. 

g,  g , The  five  false  ribs. 

h,  The  rump  bone,  or  sacrum. 

i,  The  hip  benes. 

UPPER  EXTREMITY. 

а.  The  collar  bone. 

б,  The  shoulder  blade. 

c,  The  upper  arm  bone. 

d,  The  radius. 

e,  The  ulna. 

/,  The  carpus,  or  wrist. 

g,  The  botips  of  the  hand. 

h,  1st  row  of  finger  bones. 

i,  2nd  row  of  finger  bones. 
le,  3d  row  of  finger  bones. 

/,  The  bones  ol  the  thumb. 

LOWER  EXTREMITY. 

а.  The  thigh  bone. 

б,  The  knee  pan. 

c,  The  tibia,  or  large  bone  of 

the  leg. 

d,  The  fibula,  or  small  boDe 

of  the  leg. 

e,  The  heel_  bone. 

/,  The  bones  ol  the  instep. 

g,  The  bones  of  the  foot. 

h,  The  first  row  of  toe  bones. 

i,  The  second  row  of  toe 

bones. 

k,  The  third  row  ol  toe  bones. 


ANATOMICAL  CLASS  BOOK. 


Fig.  2. 


J1  back  view  of  the  male 
skeleton. 

THE  HEAD. 

a,  The  parietal  bone. 

b,  The  occipital  bone. 

c,  The  temporal  bone. 

d,  The  cheek  bone. 

e,  The  lower  jaw  bone. 

NECK  AND  TRUNK. 

a,  The  bones-of  the  neck. 

b,  The  bones  of  the  back. 

c,  The  bones  of  the  loins. 

d,  The  hip  bone. 

e,  The  sacrum. 

UPPER  EXTREMITY. 

d a.  The  collar  bone. 

b,  The  blade  bone. 

c,  The  upper  bone  of  the 

arm. 

i6  d,  The  radius. 

V e,  The  ulna. 

Jb  f,  The  bones  of  the  wrist. 

i g,  The  bones  of  the  hand. 

/q  h.  The  first  row  of  finger 

bones. 

i,  The  second  row  of  finger 
bones. 

k,  The  third  row  of  finger 

bones. 

l,  The  bones  of  the  thumb. 

LOWER  EXTREMITY. 

a,  The  thigh  bone. 

b,  The  large  bone  of  the 

leg. 

c,  The  small  bone  of  the 

leg. 

d,  The  heel  bone. 

e,  The  bones  of  the  instep. 

f,  The  bones  of  the  toes. 


ANATOMICAL  CLASS  BOOK. 


9 


THE  CONNEXION  OF  BONES. 

When  united  with  one  another,  in  a way  to  admit  of 
motion,  the  union  is  termed  diartlirosis.  Bones  united  in 
a manner  admitting  of  no  motion  at  all,  are  said  to  be 
connected  by  synarthrosis.  And  when  they  are  joined  by 
the  intervention  of  any  substance,  it  is  called  a union  by 
symphysis. 

The  round  head  of  the  thigh  bone,  rolling  in  its  deep 
socket,  is  an  example  of  the  moveable  connexion,  or 
diarthrosis.  All  the  bones  of  the  head  present  a union 
by  synarthrosis.  In  the  racking,  or  twisting  motion  of 
the  vertebra  of  the  spine,  we  find  an  illustration  of  the 
last  division  ; between  every  two  bones,  there  is  an  elastic 
substance  to  keep  them  from  coming  in  contact;  this  is 
symphysis. 

STRUCTURE. 

All  the  large,  round  bones,  particularly  of  the  arms  and 
legs,  are  hollow,  for  two  purposes,  — viz.  1st,  because 
they  are  stronger  for  being  hollow;  and  secondly,  they 
are  store-houses.  The  marrow  is  not  placed  in  the  cavi- 
ties to  keep  the  bones  from  being  brittle,  but  to  supply  the 
system  with  food  when  the  stomach  cannot,  or  does  not 
perform  its  digestive  office. 

During  a long  course  of  sickness,  we  take  little  or  no 
food;  — but  as  nutriment  must  be  provided,  to  keep  a 
proper  quantity  of  blood  in  existence,  — where  does  it 
come  from?  Under  such  circumstances,  the  marrow, 
which  has  been  in  store  from  the  hour  of  birth,  for  such 
an  emergency,  is  now  carried  from  the  bones  and  convert- 
ed into  blood.  When  that  has  been  exhausted,  then  the 
fat,  wherever  it  exists,  is  next  taken,  — till  tira  body  be- 
comes almost  a skeleton. 

This  is  the  reason  a sick  person  becomes  poor  and  lean. 
A scanty  supply  of  food,  leads  to  the  same  result,  hence 


10 


ANATOMICAL  CLASS  BOOK. 


horses  and  other  animals  are  poor,  because  they  are  partly 
nourished,  by  converting  a part  of  their  own  bodies  into 
food.  As  soon  as  the  stomach  is  abundantly  supplied 
again,  and  is  able  to  pursue  its  accustomed  labor,  the 
marrow  and  fat,  which  were  borrowed,  are  all  returned 
and  packed  precisely  as  they  were  before. 

BONES  or  THE  SKULL. 

The  head  is  divided,  in  the  first  place,  into  cranium  and 
face. 

It  is  a curious  fact,  that  no  two  heads  are  shaped  pre- 
cisely alike;  indeed,  there  is  nearly  as  much  diversity 
in  this  respect,  as  there  are  expressions  of  the  face. 
During  the  early  periods  of  infancy,  the  bones  are  so 
flexible,  that  the  skull  may  be  moulded  into  various  forms, 
without  injury  to  the  brain.  Many  barbarous  nations, 
from  immemorial  time,  have  practised  the  art  of  changing 
the  natural  shape  of  the  heads  of  their  children,  either  to 
give  them  some  characteristic  of  the  tribe  to  which  they 
belong,  or  to  render  them  more  beautiful,  according  to 
their  rude  conceptions  of  that  quality.  Observation  on 
the  natural  differences  presented  in  the  skull,  first  gave 
rise  to  the  study  of  craniology,  which  was  refined  upon, 
till  it  has  finally  resulted  in  the  modern  science  of  phre- 
nology. 

Calvaria , is  a term  to  express  the  top,  or  convexity  of 
the  head.  The  forehead  is  the  sinciput,  and  the  back 
part,  the  occiput. 

forehead.  — Os  frontis. 

Havingjremarked  that  the  skull  is  composed  of  eight 
bones,  it  is  only  necessary  to  describe  them  individually, 
in  a very  general  manner.  The  os  frontis  is  a single 
bone  in  the  adult,  though  in  infancy  it  was  in  two  pieces. 


ANATOMICAL  CLASS  BOOK. 


11 


Though  thin  and  delicate,  it  is  in  two  plates,  whose  flat 
surfaces  have  between  them  a porous  space,  called  diploe, 
where  the  blood  vessels  are  safely  lodged  for  nourishing 
it.  Over  each  eye,  it  throws  out  a protuberance,  marked 
by  the  eyebrows ; — and  within  the  orbit,  a thin  sheet- 
like process  juts  backward,  to  support  the  brain  from 
pressing-on  the  globe  of  the  eye.  Between  the  two  plates, 
on  a vertical  line  with  the  nose,  and  just  between  the 
arched  ridges,  the  two  plates  recede  from  each  other,  so 
far  as  to  leave  a large  cavity,  — the  frontal  sinus,  which 
freely  communicates  with  the  two  nostrils,  although  a par- 
tition, extends  from  the  nose  up  through  the  chamber.  On 
this  apartment,  seems  to  depend  the  strength  of  the  voice. 

Fig.  3 

Explanations  of  Fig.  3. 
Front  view  of  the  single 
bone  constituting  the  fore- 
head : a,  a,  mark  the  place  of 
the  frontal  sinus,  or  vocal 
cavity : b , the  temporal 

ridge;  c,  the  nasal  process, 
where  the  bones  of  the  nose 
are  joined  ; e,  e,  the  external 
angular  processes  f,  f,  the 
orbitar  plates,  above  the  eye, 
to  sustain  the  brain. 


It  is  a drum-barrel,  in  effect,  being  for  the  purpose  of 
reverberating  the  sound,  by  which  its  sonorous  power  is 
increased.  While  suffering  from  a severe  cold,  the  char- 
acter of  the  voice  is  changed,  and  it  is  usual  to  remark 
the  person  talks  through  the  nose.  This  alteration,  how- 
ever, is  to  be  imputed  to  the  closing  up  of  the  passage, 
between  the  nose  and  sinus,  which  wholly  prevents  the 
sound  from  penetrating  the  only  spot  in  which  its  volume 


12 


ANATOMICAL  CLASS  BOOK. 


or  tone  can  be  increased.  Snuff  takers,  by  the  practice 
of  a vile  habit,  very  much  impair,  and  in  protracted  cases, 
completely  ruin  their  voices,  by  obstructing  the  canal. 

wall,  or  parietal  bones.  — Ossa  parietalia. 

These  are  on  one  side  convex,  and  concave  on  the 
other,  and  of  a square  figure.  They  lie  on  each  side  of 
the  head,  above  the  ears,  and  sustain  the  office  of  walls  : 
small  holes  are  discoverable  through  one  or  both  of  them, 
through  which  veins  return  blood  to  the  great  canal  with- 
in the  skull. 


occipital  bone.  — Os  occipitis. 

Of  all  the  cranial  bones,  this  is  the  strongest,  thickest, 
and  most  compact.  It  needs  to  be  so,  inasmuch  as  many 
large  muscles  on  the  back  of  the  neck,  are  inserted  into 
it.  Its  shape  is  very  much  like  a skimmer,  having  one 
large  hole  in  it,  about  an  inch  in  diameter,  through  which 
the  spinal  marrow  passes  out  from  the  brain,  on  its  pass- 
age down  the  spine, — hereafter  to  be  noticed.  After 
these  remarks,  it  will  be  inferred  that  its  locality  is  at  the 
back  and  lower  part  of  the  skull. 

WEDGE,  OR  SPHENOID  BONE.  Os  SpllCTloidcS. 

Being  entirely  concealed,  unless  the  skull  is  turned 
bottom  upwards,  some  difficulty  is  found  in  learni  ng  its  re- 
lations. Nearly  ail  writers  have  compared  it  to  a bat, 
with  wide  spread  wings.  Through  it,  many  nerves  and 
vessels  pass  out ; particularly  the  optic  nerves,  and  those 
which  supply  the  teeth,  often  so  painful,  in  the  under  jaw. 

TEMPLE,  OR  TEMPORAL  BONES.  QsSd  tcmporum. 

On  these  bones,  there  being  one  on  each  side,  the 
ears  are  fixed.  They  stand  between  the  os  f runtis , parietal 


ANATOMICAL  CLASS  BOOK. 


13 


Explanations  of  Fig.  4. 
a the  thin  squamous  portion 
of  the  temporal  bone,  joining  the 
skull,  on  a line  with  the  top  of  the 
ear;  6,  the  zygomatic  process, 
which  meets  the  cheek  bone ; c, 
a cavity  in  which  the  lower  jaw 
is  articulated  ; d,  the  external 
opening  of  the  ear;  e,  (h  e styloid 
process  ; f,  the  vaginal  process  ; 
g,  the  mastoid  process. 

and  sphcenoid  bones,  — reaching  a little  way  up  the  tem- 
ple. In  one  part  of  these  irregularly  shaped  bones,  the 
splendid  apparatus  of  the  organ  of  hearing  is  contained, 
which  will  be  fully  explained  in  the  proper  place.  Here 
is  one  quite  prominent  process,  called  the  mastoid,  which 
may  be  felt  behind  the  ear,  to  which  the  muscle  is  fixed 
that  brings  the  head  forward,  as  in  bowing. 

sieve,  on  ethmoid  noNE.  — Os  ctlimoides. 

Because  it  is  perforated  with  many  holes,  like  the  top 
of  a pepper-box,  or  sieve,  it  has  received  its  present  name. 
It  lies  horrizontallv,  on  a level  with  the  eyes,  — being 
over  the  nose,  and  has  the  front  lobes  of  the  brain  resting 
upon  it.  Through  the  numerous  orifices,  fine  threads  of 
nerves,  the  olfactories,  pass  into  the  nasal  cavities,  to 
constitute  the  sense  of  smelling. 

SEAMS  OF  THE  HEAD,  OR  SUTURES. 

All  the  bones  of  the  head  are  interlocked  by  ragged 
edges,  called  sutures.  When  one  over-laps  another,  as  in 
the  case  of  a part  of  the  temporal,  over  the  parietal  bone, 
it  is  termed  a false  suture.  All  the  true  sutures  are  zig- 
zag lines,  seen  on  the  top  and  sides  of  the  head. 


14 


ANATOMICAL  CLASS  BOOK. 


One  of  these  lines,  reaching  from  one  ear  to  the  other, 
over  the  top  of  the  skull,  is  the  coronal  suture,  — so  called 
because  an  ornament  was  placed  there,  by  the  ancients. 
The  os  frontis  meets  the  ends  of  the  parietal  bones  to 
make  this  suture. 


On  the  back  of  the  head,  the  occipital  bone  is  united  to 
a portion  of  the  temple,  and  the  wall  bones,  by  the  lamb- 
doidal  suture,  — which  has  its  name  from  its  resemblance 
to  the  Greek  letter  L. 

Between  the  parietal,  or  wall  bones,  exactly  on  the 
highest  point  of  the  arch  of  the  skull,  on  a line  with  the 
nose,  and,  consequently,  equidistant  from  both  ears,  is  the 
sagittal  suture,  — taking  its  name  from  a fanciful  resem- 
blance to  an  arrow,  lying  between  the  bow  and  string. 

There  are  several  other  sutures,  but  it  is  not  very  im- 
portant to  be  particular  in  their  description.  At  birth,  the 
pieces  composing  the  head,  are  small,  and  imperfectly 
formed.  As  we  increase  in  growth,  the  bones  also  in- 
crease in  circumference,  till  their  edges  finally  meet  and 
form  the  suture. 


Explanations  of  Fig.  5. 

a,  a,  the  coronal  suture  ; 

b,  sagittal  suture  ; c,  the 
lainbdoidal  suture;  d,  d, 
ossa  triquetra,  small,  rag- 
ged bones,  occasionally 
iound  in  some  skulls,  lying 
in  the  last  mentioned  su- 
ture; e,  e,  portions  of  the 
temporal  bone,  overlapping 
the  walls. 


ANATOMICAL  CLASS  BOOK. 


15 


When  infants  labor  under  a dropsy  of  the  brain,  the 
accumulation  of  water  is  often  so  great,  that  the  head  of 
the  poor  child  is  enormously  enlarged.  Such  a vast  col- 
lection could  not  be  contained  in  the  head,  if  the  bones 
had  been  united.  Being  only  slightly  attached  at  differ- 
ent places,  or,  perhaps,  not  at -all,  the  membranes  on  the 
inside,  are  put  upon  the  stretch,  and  the  bones  offering  no 
resistance,  are  actually  pressed  out  of  place.  An  enlarge- 
ment of  the  head  never  takes  place,  after  the  sutures  are 
formed,  though  there  may  be  a collection  of  water  in  the 
cavities  of  the  brain. 

In  preparing  the  skulls  of  animals  for  a cabinet,  the 
mode  of  opening  the  seams  oi  sutures,  that  the  shape  of 
each  bone  may  be  seen,  it  is  usual  to  fill  them  with  dry 
beans,  perfectly  full,  and  after  having  been  placed  in  warm 
water,  they  swell  and  pry  the  whole  apart. 

From  infancy  to  the  tenth  and  twelfth  year,  the  sutures 
are  imperfect ; but  from  that  time,  to  thirty-five  and  forty, 
they  are  distinctly  marked ; but  in  old  age,  they  are  near- 
ly obliterated. 

Blows  should  by  no  means  be  given  children  on  the 
head,  either  by  the  hand,  as  in  boxing  the  ears,  or  by  sticks, 
ferrules,  and  the  like  relics  of  the  old  and  obsolete  mode 
of  school-government.  The  entire  character  and  destiny 
of  a child  may  be  altered  by  a rap  on  its  half-formed  skull. 
It  is  not  only  exceedingly  dangerous,  but  criminal,  to  be 
instrumental  in  giving  a blow  that  may  produce  such  im- 
portant changes  in  the  brain. 

THE  BONES  OF  THE  FACE. 

For  the  sake  of  order,  these  are  separated  in  those 
constituting  the  upper  and  lower  jaw.  A minute  descrip- 
tion of  the  thirteen  bones  of  the  upper  jaw,  would  be  fatigu- 
ing, and  altogether  unnecessary ; yet  some  of  the  princi. 


l(i 


ANATOMICAL  CLASS  COOK. 


pal  characteristics  of  a few  of  them,  will  assist  the  student 
in  obtaining  a more  exact  knowledge  of  other  parts. 

upper  jaw  bones.  — Ossa  maxillaria  svperiora. 

Many  irregularly  shaped  small  bones  are  united  to  the 
upper  jaw, — as  the  palate,  vomer,  c.  The  upper  jaw 
is  in  two  pieces,  on  the  arch  of  which  are  situated  the 
teeth,  in  pits,  called  alveolar  sockets,  because  they  some- 
what resemble  the  cells  of  honeycomb.  Just  above  the 
angles  of  the  mouth  a hard  protuberance  is  felt,  where 
the  cheek  bone  is  met  by  it,  which  is  hollow.  Nearly 
half  an  ounce  of  fluid  is  sometimes  secreted  in  it,  in  cases 
of  severe  inflammation,  arising  from  diseases  of  the  teeth. 
Not  unfrequently  the  roots  of  the  eye-teeth  protrude  quite 
into  it.  The  name  of  this  cavity  is  antrum.  Its  use,  in 
common  with  the  one  described  in  the  os  frontis,  is  to  as- 
sist in  strengthening  the  voice. 

cheek  bones. — Ossa  malarum. 

These  stand  between  the  last  mentioned  protuberance 
and  the  outer  angle  of  the  eye,  contributing  to  the  forma- 
tion of  the  orbits. 

bones  of  the  nose. — Ossa  nasi. 

Two  bones,  which  are  merely  convex,  slender  pieces, 
about  an  inch  in  length,  meeting  in  the  middle,  form  an 
arch,  which  thus  enables  the  nose  to  resist  hard  blows. 
The  partition  is  one  bone,  vomer,  so  called  from  its  re- 
semblance to  a ploughshare.  Sometimes  it  is  twisted 
more  towards  one  side  than  the  other,  — giving  a crooked 
or  one  sided  nose,  which  materially  influences  the  ex- 
pression of  the  face. 

Within  each  nostril,  there  are  two  distinct  bones,  called 
turbinated,  because  rolled  up  like  the  folds  of  a turban, 


ANATOMICAL  CLASS  BOOK. 


17 


but  far  more  like  a roll  of  parchment.  They  are  thin  and 
porous,  and  wound  up  in  the  manner  we  find  them,  to  oc- 
cupy less  room.  On  them  is  spread  out  the  olfactory 
nerves,  in  the  form  of  a gossamer-web.  By  this  contriv- 
ance, surface  is  gained,  without  occupying  too  much  space. 
The  turbinated  bones  in  a dog’s,  lion’s,  or  tiger’s  nose, 
were  it  possible  to  spread  them,  would  present  a broad 
surface,  it  is  supposed,  equal  to  several  square  feet;  — but 
by  being  rolled,  like  a scroll,  they  can  be  packed  in  the 
narrow  canal  of  the  nostril.  Man,  not  being  designed  to 
be  dependant,-  particularly  on  the  sense  of  smelling,  has 
small  internal  nasal  bones  : — quadrupeds,  however,  are 
wholly  guided  in  the  search  and  choice  of  food,  by  this 
sense  ; hence  the  complicated  apparatus,  so  much  superi- 
or to  our  own.  These  turbinated  bones  are  liable  to  dis- 
ease, and  are  the  seat  of  tumors  called  polypus  of  the 
nose. 

tear  bones.  — Ossa  Lachrymalia. 

There  is  one  in  each  orbit,  the  size  of  the  finger  nail,  — 
having  a groove  to  conduct  the  tears  into  the  nose. 

palate  bones. — Ossa  palatina. 

Quite  on  the  back  part  of  the  roof  of  the  mouth,  these 
jut  backward,  towards  the  throat,  having,  in  life,  a cur- 
tain or  valve  suspended  to  them,  which  prevents  fluids 
from  rushing  into  the  nose,  in  the  act  of  drinking.  Usual- 
ly, accompanying  the  misfortune  of  hare  lip,  these  bones 
are  wanting,  — which  accounts  for  the  want  of  distinct 
articulate  sounds,  in  such  persons. 

lower  jaw  bone.  — Os  maxillare  inferiora. 

All  that  is  particularly  interesting  in  this  bone,  will  be 
discovered  in  the  plate,  in  which  a vast  many  muscles  will 
2* 


ANATOMICAL  CLASS  BOOK. 


IS 


be  seen,  connected  with  it.  There  is  a canal,  the  size  of 
a knitting  needle,  running  through  it,  from  one  angle  to 
the  other,  traversed  by  a nerve  that  gives  a twig  to  the  fang 
of  each  tooth,  as  it  passes  along.  y\n  artery  also  makes 
the  same  circuit,  supplying  the  teeth  with  blood. 


BON F.  OF  THE  TONGUE.  Os  llXjoidtS. 

It  is  situated  in  the  muscles  of  the  neck,  quite  in  the 
upper  and  back  part  of  the  throat  ; its  existence  would 
hardly  be  suspected,  were  it  not  felt  by  pressing  with  the 
thumb  and  finger. 


Fig.  G. 


Explanations  of  Fig.  G. 
b,  merely  indicates  the  places  where  the 
arms,  or  processes  ot  this  bone,  are  united  to 
the  body,  a,  a,  the  arms. 


Its  shape  is  much  like  the  under  jaw,  or  the  letter  U, — - 
having  the  diameter  of  a dollar.  Besides  being  the  origin 
of  the  tongue,  moving  up  and  down,  as  the  tongue  is 
moved,  it  serves  another  important  office,  of  keeping  the 
mouth  of  the  windpipe  open,  like  a hoop  in  the  mouth  of 
a sac. 


BONES  OF  THE  EAR.  Ossicilhl  auditis , 

Each  of  these,  the  malleus,  incus,  stapes,  and  os  orbicula - 
re,  are  minutely  described  in  the  article  on  the  sense  of 
hearing. 

BONES  OF  THE  SPINE.  Vertebra. 

Twenty-four  bones,  similar  in  shape,  but  varying  in  size, 
laid  one  above  the  other,  are  collectively  called  the  spine. 
Processes,  or  arms,  extend  out  on  each  side,  on  a line  with 
the  limbs;  and  one  projecting  backward,  is  the  spinous 
process,  which  gives  the  name  to  the  whole  chain.  These 


ANATOMICAL  CLASS  BOOK. 


19 


points  are  the  levers,  by  which  the  muscles  move  the 
whole,  as  a column.  No  one  vertebra  can  be  turned  on  its 
axis,  but  the  entire  series  admit  of  a twisting  movement, 
as  demonstrated  in  all  the  attitudes  which  the  body  as- 
sumes. On  the  backside  of  the  body  of  the  blocks,  the 
union  of  the  three  arms  forms  a ring,  — and  the  twenty- 
four,  present  a canal,  through  which  the  spinal  marrow 
passes  down,  giving  off  nerves  between  every  two  bones, 
to  go  to  the  ribs  and  muscles  on  the  sides. 


Fig.  7. 


Explanations  of  Fig.  7. 

This  shows  the  connexion 
of  the  blocks  or  vertebrae, 
constituting  the  backbone,  or 
spine.  All  the  lines,  indicat- 
ed by  figures,  from  1 to  24, 
indicate  nerves,  which  come 
out  between  the  bones,  from 
the  spinal  marrow.  Fig.  9 is 
the  place  of  the  stomach  ; 20, 
15  the  liver;  24,  the  kidneys; 

18,  the  spleen  ; 23,  the  mem- 
9 brane,  around  the  border  of 
17  which,  the  intestines  adhere  ; 

11  and  12  is  the  bone  called 
1 9 os  sacrum,  which,  by  being 
prolonged  in  quadrupeds,  is 
the  tail.  Man,  being  upright, 
the  bone  is  short,  and  curved, 
and  thus  holds  up  the  organs, 
which,  by  their  weight, 
13  would  otherwise  have  a ten- 
dency to  fall  through  the  bot- 
tom of  the  pelvis. 


t- 


12 


20 


ANATOMICAL  CLASS  BOOK. 


Those  of  the  neck  are  less  confined  than  those  of  the 


back  or  loins,  in  consequence  of  the  processes  being  more 
horizontal;  otherwise  there  would  be  an  inability  to  car- 
ry the  head  towards  either  shoulder. 

Between  these  vertebras,  there  is  an  intervening  sub- 
stance exceedingly  elastic,  convexed  on  both  sides, — be- 
ing thick  in  the  centre,  and  thin  at  the  edges,  which  are 
analogous  to  cushions,  to  prevent  a sudden  jar  in  our 
movements.  These  are  the  intervertebral  substance,  rath- 
er compressible,  yet  elastic.  After  being  in  an  erect  po- 
sition considerable  time,  the  superincumbent  weight 
presses  them  down  thinner,  — so  that  a person  is  shorter  at 
night,  after  fatigue  in  walking,  than  in  the  morning,  after 
the  intervertebral  pieces  have  restored  themselves  to  their 
original  condition. 


Explanations  of  Fig.  8. 

This  is  an  accurate  drawing  of  one 
of  the  bones  of  the  spine,  at  the 
neck  : a,  is  the  body  of  the  bone  ; 
b,  the  spinous  process,  or  handle, 
which  gives  the  name  of  spine  to 
the  whole  column  ; c,  c,  the  trans- 
verse processes , to  which  the  mus 
cles  adhere,  producing  motion  ; d, 
d,  round  holes  through  the  arms  of 
the  bone,  for  safely  lodging  an  ar- 
tery, which  carries  blood  to  the 
brain;  e,  e,  the  upper,  and  f,f, 
the  under  surfaces,  which  make  ajoint  with  the  blocks  above  and  be- 
low it ; g,  the  hole  through  which  the  spinal  marrow,  or  pith  of  the 
back,  passes,  in  safety  from  the  head,  through  the  whole  chain,  of 
twenty-four  vertebra. 


A person  becomes  round  shouldered,  as  the  expression 
is,  in  consequence  of' the  elasticity  of  the  front  edge  of 
these  pads  being  overcome.  A permanent  stoop  or  bend 
of  the  back  is  the  result.  Old  age,  also  gradually 
weakens  the  elastic  power,  and  therefore  aged  men  are 
often  crooked,  infirm  and  shorter,  than  in  their  youth. 
Distortions  of  the  body,  producing  deformity,  are  refera- 


ANATOMICAL  CLASS  BOOK. 


21 


ble  to  the  want  of  spring,  or  proper  elasticity  in  these 
cushions. 

The  topmost  of  all  the  bones  of  the  spine,  is  called  the 
atlas,  because  it  supports  the  head,  as  Atlas  was  fabled  to 
support  the  globe.  It  is  a ring  of  bone,  without  a body, 
which  distinguishes  it  from  all  below  it.  With  the  skull, 
it  forms  a joint,  allowing  the  head  to  move  forward  and 
backward,  but  in  no  other  manner. 

Joining  the  atlas,  is  the  dentatus,  or  tooth-like  bone, 
having  its  name  from  the  resemblance  w'hich  a particular 
portion  of  it  bears  to  a tooth.  In  a full  grown  man,  the 
process  is  about  half  an  inch  high,  above  the  body  of  the 
bone,  — and  smooth,  jutting  up  into  the  atlas.  Around 
this  pivot,  the  head  rolls.  If,  by  any  sudden  jerk,  the  head 
is  thrown  too  violently  back  or  forward,  the  dentatus  may 
be  forced  from  its  place,  — which  would  be  a dislocation, 
or  breaking  of  the  neck,  in  popular  language.  When 
criminals  are  executed  by  hanging,  the  process  is  common- 
ly torn  from  its  place,  presses  on  the  spinal  marrow, 
which,  on  its  way  down  the  back,  passes  by  the  side  of  it, 
and  death  immediately  ensues. 

All  the  remaining  twenty-two  separate  bones,  of  which 
the  spine  is  constructed,  are  called,  simply,  vertebrae. 

RIBS  AND  BONES  OF  THE  CHEST  — CostCB. 

Twentyfour  ribs,  seven  of  which  are  in  contact  with 
the  spine,  behind,  and  the  breast  bone  in  front,  form  the 
thorax  or  chest.  Each  of  the  ribs  has  a regular  joint,  to 
allow  the  chest  to  be  enlarged  and  diminished,  in  breath- 
ing : — a vulgar  notion  exists  that  males  have  one  rib  less 
than  females,  — ow'ing  to  the  circumstance  of  one  of  them 
having  been  taken  from  the  sideof  Adam,  for  the  creation 
of  woman  : — the  number  is  exactly  alike  in  both  sexes. 


22 


ANATOMICAL  CLASS  BOOK. 


.breast  bone  — Sternum. 

The  sternum,  or  breast  bone  in  the  front  wall  of  the 
chest,  is  narrow,  and  spongy,  not  far  from  an  inch  and 
quarter  wide  and  ten  inches  long,  — reaching  from  the 
throat  to  the  pit  of  the  stomach. 

Several  pieces  of  bone  are  joined  together  to  constitute 
it,  — but  the  lowest  point,  which  is  flexible,  is  the  most 
interesting.  It  can  be  felt  with  the  hand.  It  is  float- 
ing, as  it  were,  in  the  flesh,  being  flexible  and  yielding 
to  pressure,  As  we  advance  in  years,  it  becomes  os- 
sified, — and  if  distorted  or  forced  from  its  natural  place 
in  youth,  produces  the  most  painful  and  alarming  conse- 
quences in  age. 

If,  for  example,  a person  when  seated,  bends  the  body 
habitually  forward,  it  eventually  bends  the  point  of  the 
sternum  inward,  where  it  will  finally  remain.  The  conse- 
quence is,  — the  capacity  of  the  chest  is  diminished,  and 
diseases  of  the  lungs,  among  a catalogue  of  other  maladies, 
may  result  from  it.  Children  should  be  warned  of  this 
liability  to  disease,  before  a habit  is  formed  that  is  formi- 
dable when  confirmed. 

This  never  becomes  solid  like  other  bones,  even  in  ex- 
treme old  age.  Between  its  perpendicular  sides,  as  seen 
in  the  plate,  and  the  front  end  of  the  rib,  a strip  of  curti- 
lage is  interposed,  a kind  of  substance  which  is  familiarly 
known  by  the  name  of  gristle.  The  bony  wall  therefore, 
over  the  heart  and  lungs,  is  decidedly  the  weakest  part  of 
the  frame. 

There  is  a radical  defect  in  the  seats  of  all  the  school- 
rooms in  this  country.  There  should  be  a convexity  be- 
hind, to  fit  the  hollow  of  the  back.  The  seat  would  be 
more  comfortable,  and  prevent  the  bones  of  the  chest 
from  being  cramped  down  and  binding  the  digestive 
organs. 


ANATOMICAL  CLAPS  BOOK. 


23 


Explanations  of  Fig.  9. 

A the  place  where  the  collar  bone  is 
joined  ; C where  the  first  rib  is  articulated  ; 
c,  d,  e,  f,  g,  show  the  number  of  pieces 
which  are  united  into  one  : the  ensiform 

cartilage , or  tip  of  the  sternum,  — bent  out 
of  place,  very  frequently,  to  the  great  det- 
riment of  the  individual,  is  marked  h. 


Very  small  children,  in  schools,  become  excessively 
weary,  after  sitting  a little  time  on  stiff  benches  — are 
sleepy,  and  can  scarcely  be  kept  awake.  This  is  nature’s 
mode  of  seeking  relief  from  the  pressure  and  gravity  of 
the  chest,  which  is  confining  both  bones  and  muscles. 
They  should  certainly  be  permitted,  either  to  have  a re- 
cumbent posture,  which  is  thus  indicated,  or  they  should 
be  kept  but  a very  little  time  in  one  position.  Malforma- 
tion of  the  bones,  narrow  chests,  coughs,  ending  in  con- 
sumptions and  death  in  middle  life,  beside  a multitude  of 
minor  ills,  have  often  had  their  origin  in  the  school-room. 


BONES  OF  THE  LOINS. 

Five  of  the  last  vertebrae,  which  are  the  largest  and 
strongest  of  the  spine,  contribute  to  the  formation  of  the 
loins  or  lumbar  region. 


24 


ANATOMICAL  CLASS  BOOK. 


Fig.  10. 

Explanations  of  Fig.  10. 
This  is  a drawing  of  one  of. 
the  lumbar  vertebrae,  — in  the 
small  of  the  back,  in  common 
language  It  is  much  larger, 
and  contains  considerable  more 
substance  than  those  of  the 
back  or  neck  ; — and  it  re- 
quires to  be  so,  as  it  necessarily 
supports  the  weight  of  the  body 
above:  a is  the  body  ; b b the 
the  sui  faces  by  which  it  forms 
a joint  with  the  block  above  : 
c c a similar  surface,  to  meet 
the  one  below  ; d d the  side 
arms  or  processes,  to  which  the 
strong  muscles  ef  the  hack  are 
fastened. 


bones  of  the  hips.  — Ossa  Innominata. 

Three  bones,  the  os  sacrum  and  the  two  ossa  innominata 
or  hips,  are  so  united  together  as  to  form  a kind  of  horizon- 
tal ring  ; within  this  ring,  many  important  organs  are  found  ; 
on  the  outside  of  eacli  of  the  broad,  thin  hip  bones,  a 


deep  socket  is  seen,  in  which 
are  articulated. 


Fig.  ti- 


the heads  of  the  thigh  bones 


Explanations  of  Fig.  11. 
This  is  a drawing  of  the  lower 
part  of  the  hip  bone,  or  os  in- 
nomination,  in  which  is  seen 
the  head  of  the  thigh  bone,  tied 
into  its  socket,  by  a short  round 
cord,  to  keep  it  always  in  place. 
Were  it  not  for  this  curious 
provision,  by  a thousand  un- 
guarded' movements,  the  hip 
would  be  thrown  out  of  joint. 
a is  the  membrane  which  cov- 
ers the  joint ; b the  cord  that 
keeps  the  bone  in  its  socket ; c 
the  socket  in  the  hip  bone  ; d 
a rim  of  the  socket,  to  deepen 
it,  and  f the  thigh  bone  head  ; — 
e a binding  ligament;  6 the  point 
of  bone  on  which  we  sit. 


ANATOMICAL  CLASS  BOOK. 


25 


BONES  OF  THE  SHOULDER. ScapulcB. 

Lying  horizontally,  between  the  top  of  the  breast  bone 
and  the  tip  of  the  shoulder,  above  the  joint,  is  the  clavicle, 
or  collar  bone,  shaped  something  like  an  italic  s.  Its  use 
is  to  keep  the  arms  from  sliding  forward,  towards  the  breast, 
and  it  is  also  useful  in  sustaining  burdens,  as  when  a basket 
is  carried  on  the  shoulder.  Its  name  is  said  to  have  been 
derived  from  its  resemblance  to  an  ancient  key. 


Explanations  of 
Fig.  12. 

In  this  cut  is  seen 
the  union  of  the 
shoulder-blade,  col- 
lar bone, breast  bone 
-]Qand  the  shoulder 
joint.  These  are 
detached  from  the 
body,  hence  the 
I'll  view  is  a front  one. 
A portion  of  the  col- 
lar bone  of  the  right 
side  is  seen  also,  — 
all  the  others  being  on  the  left  side.  The  figures  from  1 to  11,  indi- 
cate the  ligaments  which  keep  them  united,  when  the  muscles  are 
dissected  away. 


Shoulder  blade  is  a familiar  name  of  a thin,  broad, 
triangular  bone,  behind  each  shoulder,  termed  scapula. 
At  the  highest  angle,  a hooked  process  stands  out,  which 
makes  a roof,  as  it  were,  over  the  shoulder  joint,  to  defend  it 
from  violence  by  the  pressure  of  burdens.  At  its  root,  and 
necessarily  on  its  underside,  is  a depression,  called  the 
glenoid  cavity,  in  which  the  head  of  the  shoulder  is 
articulated,  to  make  the  joint.  The  shoulder  blade  does 
not  touch  the  ribs,  nor  has  it  any  attachment  with  any 
other  bone  than  the  clavicle,  belonging  to  the  chest.  It 
lies  on  a cushing  of  a muscle,  and  is  moved  in  various 
directions  in  every  motion  of  the  arm.  If  the  arm  is  raised, 
carried  either  forward  or  backward,  down  or  up,  the  mo- 
3 


26 


ANATOMICAL  CLASS  BOOK. 


tion  of  the  shoulder  blade  may  be  distinctly  felt  through 
the  skin. 

bones  of  the  arm.  — Ossa  Humeri. 

Os  liumcri  and  os  brachii  are  names  given  by  the  books, 
to  the  arm  bone.  There  is  nothing  particularly  interest' 
ing  in  its  anatomy.  At  the  upper  end  is  a large  ball,  that 
rolls  in  the  socket  of  the  shoulder  blade  ; and  at  the  other 
extremity  it  is  flattened,  to  receive  the  fore  arm,  with  which 
it  makes  a ginglymus  or  hinge  joint,  admitting  only  of  two 
motions,  flexion  and  extension,  similar  to  motions  describ- 
ed  by  a door,  swinging  on  its  hinges.  To  this  bone,  a 
principal  part  of  the  muscles  are  attached  which  produce 
the  movements  of  the  limb. 

Fig. 13. 

Explanation  of  Fig.  13. 
Short  ligaments  of  the  elbow 
are  here  demonstrated  : the 

wonder  is,  how  the  elbow  joint 

1 can  ever  be  dislocated,  without 

2 entirely  ruining  the  whole  liga- 
mentary arrangement.  The 

^ figures  from  1 to  4,  not  only 
give  the  locality  of  each  liga- 
ment, but  even  the  figure. 


BONES  OF  THE  FORE  ARM.  Radii  et  TJlncC . 


Two  bones  are  in  the  fore-arm,  between  the  elbow  and 
wrist,  lying  side  by  side  : that  on  the  upper  side,  on  a 
line  with  the  thumb,  is  the  radius,  so  named  from  its  re- 
semblance to  the  spoke  of  a wheel.  It  is  sometimes  termed 
the  manubrium  manus,  or  handle  of  the  hand,  because  the 
hand  is  fastened  to  its  lower  end,  and  its  upper  one  has  but 
little  or  nothing  to  do  with  the  composition  of  the  elbow 
joint.  The  radius  rolls  to  and  fro,  carrying  the  hand  with 
it,  while  its  fellow,  ulna  or  cubit,  so  named  because  it  was 


ANATOMICAL  CLASS  BOOK. 


27 


used  for  a measure,  is  curiously  articulated  to  the  elbow, 
but  does  not  reach  the  hand. 

On  these  two  bones,  a vast  number  of  perplexing  mus- 
cles take  their  rise,  which  produce  the  multitude  of  short, 
quick  or  strong  motions  of  the  hand  and  fingers. 

When  the  palm  of  the  hand  faces  backward,  it  being 
supposed  that  the  arm  is  pendulous,  by  the  side,  it  is 
called  pronation.  When  it  faces  forward,  the  thumb  be- 
ing outside,  it  is  si/pination.  Those  muscles  which  pro- 
duce these  movements,  are  pronators  and  supinators. 

BONES  OF  THE  WRIST.  OsSU  Carpi. 

Eight  little  bones,  whose  shapes  cannot  be  well  describ- 
ed, placed  in  two  rows,  form  the  wrist.  On  the  back  side, 

Fig.  14.  j t. 

f: 

Explanation  of  Fig.  14. 
i This  diagram  shows  the  connexion 
of  the  little  bones  of  the  carpus  or 
wrist,  with  the  two  long  bones  of  the 
fore-arm.  1 the  ulna;  2 radius;  3 
scaphoides ; 4 lunar e ■;  5 cuneiforme ; 
6 pisiforme ; 7 trapezium  ; 8 trape- 
ziodes ; 9 magnum.  The  letters 
mark  the  ligaments  which  tie  them 
together. 

10 

8 9 

they  are  arched,  actually  reminding  one  of  irregular  sized 
stones,  so  put  together  as  to  resemble  a piece  of  masonry. 
On  the  inside,  they  make  a canal,  through  which  the  ten- 
dons of  the  muscles  glide  along  to  the  fingers. 


28 


ANATOMICAL  CLASS  BOOK. 


Fig.  15. 

b a 

Explanation  of  Fig.  15. 
Another  plan  of  the  bones  of 
tlie  wrist,  showing  them  placed 
in  two  rows.  This  is  a back 
e view  of  the  carpus  of  the  right 
hand,  a the  boat  shaped  bone ; 
b the  half  muon  shaped  ; c the 
wedge  shaped;  d the  pea 
shaped;  which  make  the  up- 
per row,  joining  the  fore  arm. 
In  the  second  row,  are  the  four 
others,  which  are  united,  by  a joint,  to  the  palm  of  the  hand. 

Their  names  are  navicular e,  lunar c,  cunciforme,  orbicu- 
lare,  trapezium,  trapeziodes,  magnum,  and  uneiforme. 


BONES  OF  THE  PALM. Metacarpus. 

A detailed  account  of  the  shape  and  size  of  the  bones 
of  the  metacarpus,  or  palm,  would  seem  to  be  unnecessary, 
as  every  person  can  ascertain  their  number  and  relations 
by  feeling  his  own  hands;  the  plan,  however,  is  inserted. 
Fi?.  1(5. 

Explanation  of  Fig.  16. 
Four  metacarpal  bones,  side  by 
side,  precisely  as  they  are  placed, 
and  of  the  true  shape,  forming  the 
palm  of  the  hand,  are  seen  in  (his 
figure.  The  metacarpal  bone  of 
the  thumb  is  seen  in  Fig.  17, 
marked  a. 


ANATOMICAL  CLASS  BOOK. 


29 


Fig.  17. 


Explanation  of  Fig.  1*. 

There  are  but  three  bones  in  the  thumb,  which 
are  larger  than  those  in  the  fingers,  because  it  was 
designed  to  oppose  them,  and  therefore  possesses  a 
structure  quite  different.  To  these  three,  five  mus- 
cles are  attached,  a,  6,  c,  are  the  three,  but  it  should 
be  recollected  that  a really  belongs  to  the  meta- 
carpus, so  that  the  phalanges  of  the  thumb  are  two. 


Only  two  bones  exist  in  the  thumb,  but  there  are  three 
in  each  finger, — collectively  called  phalanges,  being  four- 
teen in  number. 

Fig.  18. 


3* 


Explanation  of  Fig.  18. 

Twelve  bones,  as  exhibited 
in  this  plan,  constitute  the 
a fingers  of  one  hand.  They 
are  separated  from  each 
other,  that  the  exact  form  of 
the  extremities  of  each  may 
be  seen,  a the  first  bone  of 
the  litte  finger,  b the  second, 
c the  third  : the  same  letters 
b point  out  the  three,  also, 
composing  the  index,  or  fore 
finger. 


c 


30 


ANATOMICAL  CLASS  BOOK. 


Fig.  19 


Explanation  of  Fig.  19. 

Here  is  presented  a back 
view  of  all  the  bones  of  the 
hand,  as  they  are  connected 
with  the  eight  little  bones  of  the 
wrist.  Each  bone  is  so  distinct- 
ly represented,  that  a very 
young  child  may  understand 
the  arrangement. 


Explanation  of  Fig. 

20. 

All  the  bones  of 
the  arm,  fore  arm 
and  hand,  are  here 
exhibited  in  connex- 
ion, with  reference 
to  impressing  it  on 
the  mind,  after  hav- 
ing read  a short  des- 
cription of  the  indi- 
vidual parts  of  the 
upper  extremity,  a 
is  the  head  of  the  arm 
bone,  articulated  to 
the  shoulder;  b the 
joint  or  elbow,  form- 
ed by  the  ulna  and 
lower  end  of  the  arm; 
c the  shaft  of  the  os 
humeri  or  arm  ; d 
the  radius  or  handle 
of  the  hand,  united, 
solely,  to  the  wrist ; 
e the  ulna,  which 
alone  forms  with  the 
arm,  the  joint. 


ANATOMICAL  CLASS  BOOK. 


31 


BONES  OF  TIIE  INFERIOR  EXTREMITIES.  Ossa  FcmOris. 

First,  the  os  femoris,  or  thigh  bone,  is  the  largest  and 
longest  in  the  skeleton  : indeed  it  needs  to  be,  as  it  sus- 
tains the  entire  weight  of  the  whole  body.  The  ball,  by 
which  it  is  articulated  in  the  deep  socket  of  the  hip  bone, 
appears  to  be  at  the  end  of  a branch,  standing  out  at  a 
considerable  angle  from  the  shaft,  as  seen  in  the  engraving 
of  the  skeleton.  This  is  the  neck  of  the  femoris.  Its 
lower  end  or  condyle,  is  quite  large,  to  make  a part  of  the 
knee  joint.  All  the  muscles  assisting  in  running,  walk- 
ing, or  dancing,  are  variously  connected  with  it. 

BONES  OF  THE  LEG.  — Tibia. 

Tibia  is  the  scientific  name  of  the  shin  bone,  because 
it  was  thought  to  look  like  a pipe.  United  with  the  con- 
dyle of  the  thigh  bone,  assisted  only  by  the  knee  pan,  the 
knee  joint  is  formed. 

At  the  ankle,  it  is  admirably  fitted  to  the  astragalus,  to 
permit  flexion  and  extension  of  the  foot,  as  in  walking. 
A piece  or  splint,  called  malcolar  process,  slides  down  by 
the  side  of  the  joint,  to  increase  its  strength.  The  pro- 
cess may  be  felt,  being  under  the  skin  like  a knob,  on  the 
inner  side  of  the  ankle. 

This  joint  is  very  securely  arranged,  to  prevent  luxa- 
tions : as  it  merely  moves  in  two  directions,  backward  and 
forward,  — nothing  short  of  a degree  of  violence  that  in- 
jures the  bones,  can  materially  affect  it.  Beside  its  lig- 
aments, the  tendons  of  many  muscles  contribute  to  its 
security,  strength  and  perfection. 


32 


ANATOMICAL  CLASS  BOOK. 


Fig.  21. 


Explanation  of  Fig.  21. 

These  three  plans  show  how  the  two  bones  of  the  leg  are  united 
above  the  ankle  joint — 1,  2,  3,  4,  5,  7,  7,  6 — mark  the  ligaments 
which  bind  them  so  firmly. 

Outside  of  the  tibia,  is  a long,  slender  bone,  the  fibula, 
lying  on  the  side  of  the  head  of  the  tibia,  but  having 
nothing  to  do  with  the  knee  joint ; — it  passes  down  past 
the  ankle  joint,  giving  the  same  security  to  it,  that  is  af- 
forded by  the  maleolar  process  of  the  tibia,  on  the  inside. 
Between  the  two  bones,  all  the  muscles,  and  they  are 
numerous,  arise,  which  go  to  the  foot  and  toes. 

BONES  OF  THE  INSTEF  . OsSCt  Tarsi. 

Five  bones  are  found  in  the  tarsus  or  instep,  one  of 
which  is  nearly  all  given  to  the  heel.  An  arch  is  formed 
by  the  other  four,  similar  to  the  wrist,  giving  a convexity 


ANATOMICAL  CLASS  BOOK. 


33 


Fig.  52. 


Explanation  of  Fig.  22. 


By  this  diagram,  the  skeleton  of  the  foot  will  be  clearly  under- 
stood, even  without  the  aid  of  the  bones.  Twenty-six  bones  are 
here  so  curiously  grouped  together,  that  an  arch  is  made  between 
the  heel  and  ball  of  the  great  toe  : — a,  shows  the  five  hones  of  the 
metatarsus  ; d,  e,f,  g,  and  h point  out  the  five  bonesof  the  instep  or 
tarsus  ; and  b,  c,  and  i,  indicate  the  phalanges  or  toes. 

to  the  top  of  the  foot.  On  the  under  side,  in  the  sole  of 
the  foot,  all  the  flexor  muscles  of  the  toes  are  found.  This 
structure  conduces  to  the  elasticity  of  the  step,  and  the 
weight  of  the  body  is  transmitted  to  the  ground  by  the 
spring  of  the  arch,  in  a way  to  prevent  the  injury  of  nu- 
merous organs,  by  a sudden  jar.  Each  one  of  them  has 
a specific  name,  viz.  os  calcis,  the  heel ; astragalus,  being 
part  of  the  ankle  joint,  named  from  its  likeness  to  a block 
used  by  the  Greeks,  in  playing  a game  of  chance  ; cuboidcs, 
or  square  bone  ; naviculare,  the  boat  shaped  ; and  cunei- 
forme,  or  the  wedge  shaped  bone. 

As  in  the  hand,  between  the  instep  and  toes,  is  the 
metatarsus,  in  which  are  five  bones,  placed  like  the  sticks 
of  a fan,  to  be  articulated  with  the  first  row  of  the  bones 
of  the  toes. 

Precisely  as  the  short  blocks  of  bones  are  arranged  in 
the  thumb,  so  they  are  in  the  great  toe,  being,  however, 
proportionably  larger.  There  are  two  in  this  and  three 


34 


ANATOMICAL  CLASS  BOOK. 


in  each  of  the  four  remaining  toes,  — the  whole  of  which 
are  phalanges , being  fourteen  in  all. 


Fig-  24.  Fig.  23. 


Explanation  of  Fig.  23. 

This  represents  the  bones  of 
one  toe,  as  they  stand,  in  relation 
to  each  other  — a,  the  metatarsal 
part,  concealed  in  the  muscles,  and 
bed  the  three  phalanges. 

Fig.  24  is  the  -skeleton  of  the 
great  toe  : a the  metatarsal  por- 
tion, and  b c the  phalanges. 


Sesamoid  bones,  considerably  larger  than  in  the  thumb, 
are  discoverable  on  the  under  side  of  the  first  joint  of  the 
large  toe. 


SKIN  OF  THE  BONES. Periosteum. 

Over  every  bone  is  a thin,  white  covering,  the  perioste- 
um, closely  investing  it.  Its  use  is  to  conduct  the  nutri- 
cious  vessels  and  nerves  into  the  substance  of  the  bone. 
It  serves  also  for  the  attachment  of  the  muscles,  which 
could  not  otherwise  be  fastened  to  the  smooth  surface. 
Though  apparently  insensible,  it  is  amply  furnished  with 
nerves,  arteries,  and  veins,  but  its  vitality  is  very  low. 


ANATOMICAL  CLASS  BOOK. 


35 


GROWTH  OF  THE  BONES  J — Or  OsteOgetli/. 

By  this  term,  is  understood  the  doctrine  of  the  formation 
and  growth  of  the  bones.  From  infancy,  till  the  age  of 
about  twenty  years,  they  are  constantly  undergoing  changes. 
In  fact,  they  are  completely  renewed,  many  times  in  the 
course  of  a long  life.  No  particle  of  matter  can  long  re- 
main at  rest  in  a living  system.  When  one  portion  is  re- 
moved, another  is  put  in  its  place,  so  that  by  the  circula- 
tion of  the  blood,  the  greatest  activity  prevails,  even 
among  these  earthy  portions  of  the  body. 

The  arteries,  hereafter  to  be  described,  are  the  arti- 
zans,  — carrying  whatever  is  necessary  to  promote  the 
growth,  or  to  repair  the  wastes  of  the  system.  They  also 
fashion  each  organ,  give  shape  to  every  bone,  and  sustain 
and  furnish  them  with  vitality. 

Bones  have  nerves,  but  they  are  small,  and  only  con- 
nect them  with  the  other  more  highly  organized  parts. 
When  they  are  diseased,  they  become  painful  as  the  mus- 
cles ; but  in  health,  they  are  insensible. 

As  a whole,  the  skeleton  is  merely  a frame,  on  which 
are  suspended,  or  attached,  all  the  organs  of  motion.  It  is 
full  of  joints  — and  each  bone  is  a lever,  to  be  acted  upon 
by  the  power  of  a muscle.  This,  which  in  most  of  the 
large  animals  is  in  the  centre,  in  many  of  the  smaller 
tribes,  is  on  the  outside,  in  the  form  of  a shell.  Examples 
may  be  found  in  the  turtle  and  lobster,  beetles,  &c. 

Such  a remarkable  piece  of  mechanism  as  the  skeleton, 
divested  of  a thousand  important,  wonder-working  accom- 
paniments, exhibits  in  the  clearest  light,  the  goodness  and 
wisdom  of  God.  The  fashion  of  each  bone,  and  above  all, 
the  skilful  and  nice  adjustment  of  the  whole,  and  their 
subserviency  to  the  different  fibres  and  tubes  which  are 
intimately  connected  with  this  complicated,  yet  perfect 
piece  of  architecture,  must  strike  a reflecting  mind,  most 


36 


ANATOMICAL  CLASS  BOOK. 


forcibly,  that  the  evidences  of  the  existence  of  a Supreme 
Power,  are  here  manifested  in  a most  extraordinary 
manner. 

DIFFERENCES  BETWEEN  MALE  AND  FEMALE  SKELETONS. 

Were  it  true  that  men  have  a deficient  number  of  ribs, 
there  would  be  no  difficulty  in  designating  the  skeletons 
of  different  sexes.  To  an  inexperienced  eye,  it  will  al- 
ways be  a nice  point,  to  determine  one  from  the  other. 

The  skeleton  of  the  male  is  larger  and  heavier  than 
that  of  the  female.  The  surfaces  of  the  bones  are  rougher, 
as  the  muscles  which  moved  them  were  more  strongly  de- 
veloped, and  capable  of  exerting  more  power  than  those 
of  the  other.  The  head  of  the  female,  on  an  average,  is 
smaller  than  the  male  ; the  sutures  are  less  notched;  and 
the  cavities  in  the  bone  of  the  forehead,  and  upper  jaw 
bones,  are  considerably  smaller.  All  the  limbs  are  more 
delicately  and  slenderly  formed.  Processes  are  less  prom- 
inent, and  depressions  are  comparatively  more  superficial. 

A still  stronger  difference,  however,  is  found  in  the  pel- 
vis,— a kind  of  arch,  or  bony  circle,  bounded  by  the  hip 
bones.  In  females,  the  pelvis  is  much  broader  than  in 
men,  and  the  hips  are  spread  more  outwardly.  Lastly,  the 
necks  of  the  thigh  bones  are  longer,  — giving  them  the 
appearance  of  being  particularly  broad  across  the  hips  : 
thus  far,  only,  females  are  constructed,  in  the  frames  of 
their  bodies,  to  differ  very  essentially  from  the  male. 
The  breadth  of  the  pelvis,  in  connexion  ufith  the  peculi- 
arity of  a long  neck  to  the  thigh  bones,  brings  the  knees 
nearer  together. 

If  two  skeletons,  one  of  a man,  the  other  of  a woman, 
are  suspended,  it  will  be  noticed  that  the  lower  extreme- 
ties  of  the  male  would  be  nearly  parallel  to  each  other; 
whereas,  in  the  other,  the  knees  will  approximate  so  near- 


ANATOMICAL  CLASS  BOOK. 


37 


ly,  as  to  touch.  Another  difference  consists  in  the  capa- 
city of  the  chest : one  is  small,  and  the  other  is  large. 
The  bones  of  the  feet  and  hands  are  large  in  men  ; — but 
in  the  female  they  are  slender,  smooth  and  delicate.  Fi- 
nally, the  height  and  weight  would  have  an  influence  up- 
on our  judgment  in  deciding  upon  the  character  of  either. 

DISTORTIONS  TO  WHICH  THE  BONES  ARE  LIABLE. 

Many  injuries  of  the  bones  are  induced  by  the  careless- 
ness of  nurses,  in  infancy  and  the  first  years  of  childhood, 
which  have  a permanent  influence  on  the  figure  and  health 
in  after  life.  Females,  especially,  by  the  caprice  of  fash- 
ion, are  the  subjects  of  many  alarming  diseases,  arising 
from  distortions  of  the  bones.  One  of  the  most  serious 
affections,  a distortion  of  the  spine,  is  muchoftener  found 
in  females,  than  in  males.  Boys  generally  lead  an  active 
life,  — enjoying  a free  exercise  of  all  their  limbs,  in 
various  youthful  pastimes.  Girls,  by  a perverse  custom, 
are  taught  that  they  were  made  for  the  house,  and  not  for 
the  open  air.  Their  employments  are  therefore  com- 
monly of  a sedentary  kind,  necessarily  confining  them  to 
one  posture  many  hours  at  a time.  Added  to  this,  which 
is  enough  to  enfeeble  any  constitution,  their  bodies  are 
compressed  by  the  modern  modes  of  dressing,  to  such  a 
degree,  that  instead  of  naturally  expanding,  to  give  full 
play  to  the  lungs,  the  chest  is  kept  from  enlarging  its 
capacity,  by  stays,  and  closely  fitted  dresses.  The  ribs 
are  pressed  inwardly,  the  spine  prevented  from  having 
motion ; the  lungs  cramped,  and  consumptions,  inflamma- 
tions, and  other  oftentimes  incurable  maladies,  are  the 
certain  results. 

Notwithstanding  the  odium  cast  upon  the  Chinese  for 
their  ridiculous  fancy  for  the  small  feet  of  their  females, 
which  are  prevented  from  growing,  by  being  compressed 
4 


33 


ANATOMICAL  CLASS  BOOK. 


in  iron  shoes,  it  is  not  so  cruel  nor  absurd,  as  the  practice 
among  the  females  of  all  civilized  countries,  at  the  present 
day,  of  preventing  the  growth  of  the  waist. 

Physicians,  philanthropists  and  philosophers,  have  each 
exerted  themselves,  to  awaken  an  interest, — to  arouse 
females  to  a sense  of  their  danger,  but  it  has  been  to  little 
purpose.  Though  seriously  deformed,  they  cannot  be 
persuaded  to  abandon  a custom,  which,  in  their  apprehen- 
sion, improves  their  otherwise  beautiful  forms. 

We  here  introduce  the  following  drawings,  to  show 
what  is  the  actual  condition,  of  the  chest  that  has  become 
permanently  diminished  by  artificial  means,  compared  with 
one  that  has  been  developed  as  nature  intended. 

Young  ladies  require  nearly  as  much  exercise  as  boys, 
but  of  a less  violent  character,  as  their  physical  organiza- 
tion is  not  calculated,  it  is  reasonable  to  suppose,  for  se- 
vere exertions  of  the  muscles.  They  certainly  require 
loose,  easy  clothing,  that  the  bones  concerned  in  the  forma- 
tion of  the  apartment  in  which  is  placed  the  vital  ap- 
paratus, may  be  free,  unimpeded,  and  unrestrained. 

Contracted  chest. 

An  outline  is  here  presented  of  the 
chest  of  a female,  to  show  the  actual 
condition  of  the  bones,  as  they  appear 
after  death,  in  every  lady  who  has 
habitually  worn  stays. 

All  the  false  ribs,  from  the  lower  end 
of  the  breast  bone,  are  unnaturally 
cramped  inwardly  towards  the  spine, 
so  that  the  liver,  stomach  and  other  di- 
gestive organs  in  the  immediate  vicini- 
ty, are  pressed  into  such  small  compass, 
that  their  functions  are  interrupted, 
and  in  fact,  all  the  vessels,  bones,  and  viscera,  on  which  the  individ- 
ual is  constantly  depending  for  health,  are.  more  or  less  distorted 
and  enfeebled. 

Whatever  has  a tendency  to  confine  those  parts  of  the 
frame  which  were  designed  for  motion,  positively  tends  to 


ANATOMICAL  CLASS  BOOK. 


39 


Skeleton  of  a well  formed  female 
chest. 

By  comparing  the  accompanying 
plan  of  a well  developed  and  natur- 
ally proportioned  female  chest,  with 
the  frightful  skeleton  appended  to 
the  preceding  note,  the  difference 
is  strikingly  apparent.  Here  is 
breadth,  — space  for  the  lungs  to  act 
in  ; and  the  short  ribs  are  thrown 
outwardly,  instead  of  being  curved 
and  twisted  down  towards  the  spine, 
by  which  ample  space  is  afforded 
for  the  free  action  of  all  those  or- 
gans, which  in  the  other  frame, 
were  too  small  to  sustain  life. 
The  first  iriav  be  regarded  as  the 
exact  shape  and  figure  of  a short  lived  female  ; and  this  may  be 
contemplated  as  an  equally  true  model  of  the  frame  of  another,  who, 
so  far  as  life  depends  upon  a well-formed  body,  would  live  to  a good 
old  age. 

the  production  of  disease  ; it  is  therefore  of  the  highest 
interest  to  the  well  being  of  our  species,  that  an  elementa- 
ry knowledge  of  the  structure  of  the  human  body  should 
be  taught,  and  everywhere  understood,  — that  precautions 
may  be  taken  to  avoid  a threatening  danger.  Physical  ed- 
ucation is  not  only  too  much  neglected,  but  what  is  still 
more  lamentable,  scarcely  appreciated  in  this  country.  If 
parents,  in  the  first  place,  and  instructers  in  the  second, 
studied  more  the  education  of  the  body,  the  intellectual 
faculties  would  be  more  fully,  and  energetically  developed. 
Above  all,  the  young  should  be  instructed  correctly,  in 
the  knowledge  of  the  laws  of  animal  life. 

The  lungs  too  suffer, — and  in  those  cases,  which  are 
ninety  in  a hundred , where  the  stays  have  been  laced  on 
in  very  early  life,  before  the  ribs  have  become  perfectly 
ossified,  the  chest  is  never  developed  ; — it  never  assumes 
the  form  which  it  would  have  had,  were  it  not  for  this 
mechanical  restraint;  consequently,  for  want  of  capacity, 
or  in  other  words,  for  the  want  of  room,  the  lungs  are  too 


Vig.  ec. 


40 


ANATOMICAL  CLASS  BOOK. 


small  for  the  requirements  of  the  body;  — they  cannot 
oxygenate  the  blood,  — an  indispensable  vital  process. 

Corset  boards  are  quite  as  reprehensible,  though  the  in- 
juries to  which  they  give  rise,  are  less  apparent  in  the  be- 
ginning. The  busk  operates  almost  exclusively  on  the 
sternum  or  breast  bone,  which  is  easily  bent  out  of  its 
original  position,  at  its  lower  extremity. 

By  a constant  pressure  of  an  inelastic  board,  the  lower 
end  of  the  sternum,  which  juts  down  into  the  abdominal 
muscles  two  or  three  inches,  is  forced  inward,  and  be- 
coming ossified  irr  that  direction,  is  productive  of  serious 
injury  to  the  stomach,  which  lies  just  behind  it. 

A multitude  of  painful  and  protracted ' diseases,  by 
which  females  in  the  higher  walks  of  society,  in  this  age, 
are  hurried  to  an  early  grave,  have  their  origin  in  this  hor- 
rible custom  of  wearing  stays.  Thousands  upon  thou- 
sands of  young  ladies  are  the  yearly  victims,  even  in  the 
United  States,  to  consumption,  which  is  wholly  referable 
to  this  fashionable,  but  perverted  taste,  of  conforming  to 
a practice  which  has  for  its  object,  the  improvement  of 
the  female  form  ; as  though  the  Creator,  in  constructing 
the  most  beautiful  work  of  his  creation,  neglected  to  give 
that  last  finishing  process,  which  they  imagine  them- 
selves to  have  discovered,  and  which  can  alone  be  satisfac- 
tory to  the  sex. 

While  we  lament  the  tolerance  of  an  evil  in  our  coun- 
try that  sweeps  the  young,  the  beautiful,  and  the  intelligent 
to  the  tomb,  before  the  summer  of  life  has  fairly  commenc- 
ed, we  scarcely  indulge  the  hope  of  a reformation  : per- 
nicious customs  which  are  preserved  by  common  consent, 
cannot  be  easily  overcome  by  persuasion  or  argument. 

If,  notwithstanding  the  many  illustrations  given  of  the 
sad  effects  of  stays  and  busks,  by  various  philanthropic 
writers,  mothers  and  nurses  manifest  no  disposition  to  be 


ANATOMICAL  CLASS  BOOK. 


41 


influenced  by  their  opinions  and  advice,  the  duty  most 
certainly  devolves  on  all  public  teachers,  in  a delicate  and 
appropriate  manner,  to  instruct  their  pupils  in  the  first 
principles  of  preserving  health,  by  explaining  the  morbid 
effects  which  arise  from  confining  the  body  in  stays. 

One  of  the  first  lessons  in  physical  education  should  be, 
to  strip  from  the  pupil  every  unnecessary  artificial  restraint 
upon  the  body  and  limbs. 

TEETH. 

In  manhood,  there  are  thirty-two  teeth,  divided  in  the 
following  manner  : 

8 Incisores,  — or  cutting  teeth. 

4 Cuspidati, — or  dog  shaped,  — being  pointed. 

8 Bicuspides,  — or  two  pointed  double  teeth. 

8 Molares,  — or  giinding  teeth. 

4 Dentes  Sapienlis, — or  wisdom  teeth. 

The  first  set,  or  milk  teeth,  are  twenty  in  number,  ap- 
pearing from  time  to  time,  from  the  age  of  about  ten 
months,  to  three  years,  when  they  are  all  developed. 
There  are,  however,  many  variations  as  respects  the  peri- 
od of  cutting  them,  depending  on  constitutional  causes. 
When  the  roots  are  absorbed,  the  tops  fall  off  from  the 
gums,  and  the  second  set  are  protruded.  The  jaws,  in  the 
mean  time,  become  longer  and  broader,  which  allows  room 
for  an  increased  number,  of  a greater  size. 

In  the  centre  of  each  tooth,  is  a cavity,  in  which  the  pulp 
of  a nerve  lies,  and  which  is  the  seat  of  pain,  when  the 
body  of  the  tooth  is  so  decayed  as  to  expose  it  to  the  air, 
or  bring  it  in  contact  with  food.  Each  root  is  also  hollow, 
allowing  the  fibre  of  a nerve  to  communicate  with  the 
nerves  of  the  jaw,  and  blood  vessels  also  run  in  by  the 
side  of  it,  to  nourish  the  whole. 

The  enamel  is  the  outside,  hard  crust,  which  gives  the 
requisite  finish  to  the  tooth,  and  renders  it  strong  enough 
4* 


42 


ANATOMICAL  CLASS  BOOK. 


for  mastication.  This  enamel  is  much  thinner  on  the  teeth 
of  some  persons  than  on  others,  and  scaling  off,  the  bony 
part  of  the  teeth  being  exposed,  soon  falls  into  disease  by 
the  contact  and  influence  of  various  kinds  of  food,  drink, 
heat  and  colds. 

Acids  of  all  kinds  are  particularly  injurious  to  the  teeth, 
because  they  act  chemically  on  the  lime  contained  in  the 
enamel,  — destroying  the  connexion  of  the  particles,  and 
thus,  ultimately,  exposing  the  nerve.  Hot  drinks  are 
also  pernicious. 

Individuals  living  on  moderately  cool  food,  and  drinking 
cold  water,  simply,  preserve  their  teeth  in  all  their  origi- 
nal beauty  and  goodness,  to  an  advanced  period. 

Sugar  is  not  destructive  to  the  teeth,  as  generally  sup- 
posed : slaves,  on  sugar  plantations,  possess  the  finest  sets, 
uninjured,  apparently  to  extreme  old  age. 

Cold  water  only  is  advisable,  applied  with  a soft  brush, 
for  keeping  them  white,  clean  and  in  a healthful  condition. 
The  various  dentifrices,  salt,  ashes,  charcoal,  &.c,  actually 
injure  them  by  attrition  in  the  application,  and  should 
never,  therefore,  be  used.  Chewing  and  smoking  tobacco, 
is  very  destructive  to  the  teeth.  To  youth  these  few  prac- 
tical considerations  are  worth  their  recollection. 

When  the  teeth  are  all  extracted,  the  sockets  which  sup- 
ported them  are  absorbed,  and  hence  the  jaws  are  nar- 
rower, which  explains  the  reason  why,  in  old  age,  the 
mouth  is  smaller  and  the  lips  sunken  : it  also  accounts 
for  the  difficulty  with  which  words  are  articulated.  The 
tongue  being  compressed,  moves  with  less  freedom,  and 
distinct  enunciation  becomes  extremely  difficult. 


ANATOMICAL  CLASS  BOOK. 


43 


QUESTIONS. 


What  is  understood  by  Anatomy  ? 

What  is  Comparative  Anatomy  and  its  use  ? 

Into  how  many  parts  is  the  science  divided  ? 

What  is  Osteology  ? 

What  is  Syndesmology  ? 

What  is  Myology  ? 

What  is  Bursology  ? 

What  is  Angiology  ? 

What  is  Adenology  ? 

What  is  Splanchnology  ? 

What  is  Ilygrology  ? 

How  are  the  bones  classed  ? 

How  are  the  names  of  bones  derived  P 
Are  they  hollow  or  solid  ? 

What  are  processes  and  their  use  ? 

What  is  a natural  skeleton  ? 

What  is  an  artificial  skeleton? 

How  many  bones  compose  the  skeleton  ? 

How  is  the  skeleton  divided  by  anatomists  P 
How  many  bones  compose  the  skull  ? 

How  many  are  there  in  the  face  ? 

How  many  teeth  and  how  arranged  ? 

Has  the  tongue  any  bone  ? 

Is  the  sense  of  hearing  dependent  upon  bones? 

How  many  bones  compose  the  trunk  ? 

What  are  Sutures  ? 

Where  is  the  Coronal  Suture? 

How  does  the  male  differ  essentially  from  the  female  skele- 
ton ? 


44 


ANATOMICAL  CLASS  BOOK. 


Why  are  some  bones  hollow  ? 

What  is  the  use  of  marrow  ? 

How  many  bones  in  the  fore  arm  ? 

How  many  in  the  wrist? 

What  is  the  carpus  ? 

Where  is  the  metacarpus  ? 

How  many  phalanges  in  the  fingers  ? 

How  many  bones  in  the  foot? 

Are  extra  bones  ever  found  — and  if  so,  where  ? 

How  are  bones  said  to  be  united  ? 

Where  is  the  os  frontis  ? 

Of  what  use  are  the  cavities  in  the  bones  of  the  forehead 
and  cheeks  ? 

Where  is  the  occipital  bone  situated  ? 

What  circumstance  renders  the  temporal  bone  particu- 
larly interesting  ? 

What  do  you  understand  by  the  spine  ? 

Why  are  persons  taller  in  the  morning  than  at  night? 

Why  are  aged  persons  inclined  to  be  crooked,  and  shorter 
than  in  their  youth  ? 

How  many  ribs  are  there  ? 

What  is  meant  by  pronation  of  the  hand  ? 

What  by  supination  ? 

What  is  the  use  of  the  periosteum? 

What  is  osteogeny  ? 

Have  bones  any  sensibility  ? 

How  do  they  grow,  or  how  are  they  repaired  when  injured? 
What  is  the  use  of  the  skeleton  ? 

What  is  the  metatarsus? 

What  are  ligaments  ? 

How  many  bones  in  the  arm? 

How  many  teeth  in  adults  ? 

Where  is  the  sternum? 

What  is  the  use  of  the  clavicle  ? 

How  many  bones  in  the  foot  ? 

Of  what  use  is  a bone  in  the  tongue  ? 

Are  there  more  ribs  in  a male  than  in  a female  skeleton  ? 


ANATOMICAL  CLASS  BOOK 


45 


LIGAMENTS. 

OR  SYNDESMOLOGY. 

In  the  economy  of  the  system,  the  skeleton  would  have 
been  in  a very  imperfect  condition,  if  so  many  bones  were 
not  firmly  connected  together.  The  bands  and  straps 
which  so  effectually  and  strongly  connect  them,  one  with 
another,  are  called  ligaments,  and  syndcsmology  is  the 
study  or  doctrine  of  them. 

Such  is  the  prodigious  tenacity  of  the  ligaments,  that 
the  bones  are  sometimes  fractured,  before  they  are  torn 
from  their  points  of  adhesion. 

Ligaments,  like  the  bones  themselves,  are  nearly  insen- 
sible, white  and  shining,  and  commonly  short,  thin  and 
tough.  Where  the  ends  of  two  bones  meet,  as  in  the  con- 
struction of  a joint,  their  situation  is  maintained  by  liga- 
ments running  from  one  to  the  other.  Possessing  but  a 
very  slight  degree  of  elasticity,  the  joints  do  not  become 
loose  or  shackling,  unless  extension  is  maintained  a very 
long  time. 

Were  it  not  for  ligaments,  the  bones  of  our  bodies  would 
fall  down  by  their  own  weight.  A natural  skeleton  is 
one  on  which  they  have  been  preserved,  with  reference  to 
showing  the  precise  connexion  of  the  bones. 

Some  ligaments  are  exceedingly  interesting,  from  the 


4(5 


ANATOMICAL  CLASS  BOOK. 


Explanation  of  Fig.  27. 
e,  J,  are  the  crucials  or  cross  liga- 
ments, so  remarkable  in  structure  and 
office  ; f,  the  tendon  of  an  extensor 
muscle;  c,  the  head  of  the  fibula , 
joining  the  side  of  the  shin  bone  ; a, 
the  articulating  surface  of  the  lower 
end  of  the  thigh  bone,  covered  by  the 
knee  pan  ; b,  refers  to  the  broad  liga- 
ment, turned  down  from  the  joint  to 
expose  the  cross  ligaments,  having 
the  knee  pan  on  it. 


circumstance  that  they  keep  a joint  from  bending  the 
wrong  way.  The  knee  would  be  the  weakest,  and  most 
liable  to  get  out  of  order,  of  any,  were  it  not  for  its  nume- 
rous ligaments. 

Within  this  joint,  two  ligaments  are  so  arranged,  that 
they  cross  each  other,  like  the  legs  of  a saw-horse,  com- 
pletely preventing  the  leg  from  being  carried  too  far  back- 
ward or  forward.  The  lateral  ligaments  guard  against  dis- 
locations on  either  side. 

One  single  round  ligament  fastened  on  the  head  of  the 
thigh  bone,  ties  it  into  the  centre  of  its  socket,  keeping  it 
always  in  place,  however  much  the  limb  be  moved  in 
opposite  directions. 

Ligaments  exist  wherever  two  bones  meet  at  their  ex- 
tremities, and  also  abound  in  the  cavities  of  the  body, 
in  the  form  of  flat  or  round  cords,  to  sustain  the  weight 
of  important  organs,  as  the  liver,  spleen,  and  pancreas. 
Without  these  supports  the  liver  would  inevitably  fall 
down,  from  its  place  just  under  and  behind  the  false  ribs 
of  the  right  side,  upon  the  hollow  organs  below.  The 


ANATOMICAL  CLASS  BOOK. 


47 


FiS.  28. 


Explanation  of  Fig.  28. 

Complex  as  the  ligaments  appear 
in  this  plan,  there  is  certainly  an 
admirable  simplicity,  conducing  ex- 
actly to  the  perfection  of  the  frame 
of  the  hand.  Each  letter,  as  in 
other  diagrams,  shows  the  place  of 
each  individual  ligament,  as  found 
on  dissection,  joined  to  the  bones, 
which  are  thus  drawn  together  like 
so  many  wedges.  it  would  he 
utterly  impossible  for  the  most  in- 
genious mechanic  to  take  the  dry 
bones  and  secure  (hem  together  by 
wires,  clasps,  rivets  or  straps,  so 
strongly  as  nature  has  done  by  means 
of  these  little  shining  ligaments. 


gall-bladder  is  tied  lo  the  liver  by  a ligament ; the  intes- 
tines are  kept  in  their  places  by  ligaments  ; — the  stomach, 
too,  without  ligaments  would  soon  be  thrown  by  its  own 
muscular  exertions,  during  digestion,  from  its  natural  lo- 
cality. Even  in  the  skull,  ligaments  assuming  various 
forms,  support  the  lobes  of  the  brain,  protect  vessels,  and 
give  strength  to  the  architecture  of  the  head  during  the 
first  years  of  life.  Indeed,  ligaments  are  indispensable 
throughout  the  animal  frame. 

By  means  of  them,  the  small  hones  of  the  foot  are  kept 
firmly  together  in  the  shape  of  an  arch,  in  the  instep  : — 
otherwise  the  weight  of  the  body,  in  the  exercise  of  walk- 
ing, would  crush  them  apart,  and  forever  destroy  their 
curious  connexion. 


48 


ANATOMICAL  CLASS  BOOK. 


Fig.  29. 


Explanation  of  Fig.  29. 

By  this  drawing,  which  is  true  to 
nature,  it  will  be  seen,  distinctly,  how 
the  bones  of  the  instep  and  ankle,  are 
articulated;  — how  the  instep  and  pha- 
langes or  toe  bones  meet;  and  lastly, 
the  small  letters  direct  the  eye  to  the 
locality  of  each  ligament,  which  assists 
in  binding  this  congeries  of  large  and 
small  blocks  firmly  together,  like  a 
pavement. 

g Incases  of  club-foot,  the  ligaments 
are  very  much  deranged,  in  conse- 
quence of  the  distortion  and  displace- 
ment of  the  bones.  But,  however  for- 
midable the  case  may  appear,  if  season- 
able exertion  is  made,  the  very  worst 
club-foot  may  be  re-modelled  by  an  iron 
shoe,  provided  with  metallic  rods  run- 
ning up  by  the  sides  of  the  ankle,  so 
that  both  the  apparatus  and  bones  may 

11  be  kept  in  place.  Without  the  advice 
of  a surgeon,  any  ingenious  mechanic 
can  remedy  a malformation  of  the  foot, 
if  the  trial  is  commenced  while  th# 
bones  are  imperfectly  ossified. 


By  ligaments  the  wrist  is  fastened  to  the  arm,  indepen- 
pendently  of  muscles ; the  shoulder  to  the  shoulder  blade ; — 
the  head  to  the  first  bone  of  the  neck  ; — the  ribs  (o  the 
spine,  and  the  vertebrae  to  each  other.  The  office,  there- 
fore, which  these  deep  seated,  almost  unnoticed  straps 
hold,  in  binding  the  whole  frame  together,  cannot  be 
overlooked  by  any  one  who  contemplates  the  marvellous 
work  of  God,  as  exhibited  in  our  own  complex,  yet  beau- 
tifully fashioned  bodies. 


ANATOMICAL  CLASS  BOOK. 


40 


Fig.  30. 


Explanation  of  Fig.  30. 

Having;  completed  a general  description  of  all  the  individual  bones, 
and  exhibited  some  of  the  principal  ligaments  of  the  limbs,  the  object 
of  this  third  drawing  of  an  entire  skeleton,  is  first,  to  give  aside  view 
of  the  parts  adverted  to  in  the  foregoing  pages,  — without  letters  or 
references  to  deface  the  engraving,  or  to  perplex  the  mind.  The 
peculiar  attitude  of  the  figure  was  given  it  by  the  artist,  merely  be- 
cause a larger  sized  drawing  could  thus  be  given  in  a little  space. 


5 


50 


ANATOMICAL  CLASS  BOOS, 


THE  MUSCLES. 

OR  MYOLOGY. 

An  interesting  department  of  anatomy  is  called  myology r 
or  the  doctrine  of  the  muscles. 

We  would  by  no  means  surfeit  our  young  readers  with 
the  consideration  of  subjects  which  are  only  considered 
valuable  to  the  anatomist : — but  we  wish  general  inquirers 
to  participate  in  some  of  those  sublime  manifestations  of  the 
all-creative  Power,  presented  in  the  mechanism  of  animal 
bodies,  which  have  too  long  been  locked  up  in  libraries. 

All  that  pertains  to  anatomy,  either  human  or  compara- 
tive, possesses  the  highest  degree  of  interest. 

We  are  not  so  enthusiastic  as  to  suppose  that  every 
body  can  be  induced  to  feel  so  earnestly  devoted  to  this 
science  as  ourselves; — nor  is  the  desire  entertained  of 
making  dry  bones  a fashionable  topic  of  general  conversa- 
tion ; but  we  do  most  fervently  hope  that  the  leading 
principles  of  anatomical  and  physiological  knowledge 
will  be  diffused;  will  yet  be  taught  in  all  the  schools  of 
this  country. 

The  advantages  to  youth,  arising  from  a public  dissemi- 
nation of  these  sciences,  will  be  very  numerous,  as  it  will 
lead  the  young  to  correct  view's:  — it  will  dispel  that 
vulgar  kind  of  mystery  in  w'hich  the  functions  of  individual 
organs  are  enveloped  : — it  will  strengthen  the  morals, 
elevate  the  mind,  and  finally,  be  one  of  the  surest  means 
of  fixing  the  attention  to  the  considerations  of  the  char- 
acter and  Omnipotence  of  God. 


ANATOMICAL  CLASS  BOOK. 


51 


Ordinarily,  there  is  more  vulgar  curiosity,  seeking  to 
be  gratified  on  a variety  of  topics,  embraced  in  these 
valuable  sciences,  than  in  almost  any  other.  Next  to 
the  insane  expectation  of  converting  the  base  metals  into 
gold  ; — the  desire  and  the  hope  to  prolong  the  period  of 
life,  to  raise  the  dead,  and  to  avert  disease,  has  always 
been  founded  on  a limited  and  false  knowledge  of  anato- 
my. Those  who  are  truly  learned  in  the  science,  dis- 
cover the  impossibility  of  maintaining  never  failing  youth  : 
they  are  convinced  of  the  necessity  of  death,  the  only 
means  of  allowing  a succession  of  beings;  — the  only 
means  by  which  matter  can  assume  the  forms  that  insure 
this  unfailing  result. 

Our  bodies  are  indeed  marvellously  constructed  ; the 
materials  of  which  they  are  composed,  possess  the  most 
opposite  characters,  — and  the  effects  produced  by  the 
harmonious  operation  of  each  fibre,  however  minute 
or  remote,  contributes  something  towards  the  perfec- 
tion of  the  whole.  The  moving  powers,  the  self-acting 
levers,  and  the  invisible  something  which  guides  the 
movement,  or  limits  the  duration  of  action,  belong  to 
another  inquiry ; yet,  before  arriving  there,  it  is  first 
necessary  to  investigate  the  instruments  of  motion,  the 
muscles. 

MUSCLES. 

There  are  527  muscles  in  man,  257  being  in  pairs. 

Wherever  there  is  a joint  to  be  flexed,  a bone  to  be 
moved,  or  a motion  of  any  kind  to  be  effected,  it  is  entirely 
executed  by  muscles.  Muscles  are,  in  popular  language, 
Jlcsh;  but  instead  of  being  an  irregular  mass,  as  too  com- 
monly supposed,  exact  order  is  maintained ; a certain 
number  of  threads  are  invariably  deposited,  with  syste. 
matic  attachments,  with  reference  to  a specific  kind  of 
motion. 


52 


ANATOMICAL  CLASS  BOOK. 


Chance  has  nothing  to  do  with  the  muscular  tissues. 
Eacli  muscle  is  formed  by  an  exact  rule,  from  which 
nature  never  departs,  without  exhibiting  a monster, 
whose  motions  are  so  far  a deviation  from  the  species,  that 
the  individual  is  physically  defective,  and  incapable  of 
transmiting  it  to  its  offspring.  A majority  of  the  cases  in 
which  too  many  or  too  few  organs  are  seen,  are  to  be  im- 
puted to  incidental  causes,  which  prevented  nature  from 
completing  those  portions,  the  absence  or  excess  of 
which  constitutes  the  essential  characteristics  of  a species. 
The  laws  of  the  animal  economy  are  immutable. 

The  figures  of  the  muscles  are  as  various  as  possible, 
some  being  round,  others  square,  triangular,  or  flat  like  a 
ribbon.  In  length  too,  the  variations  are  remarkable. 
Belonging  to  the  vocal  box,  the  (larynx,)  the  muscles, 
opening  and  closing  the  rima  glotidis,  to  vary  the  strength 
of  voice,  are  only  about  an  eighth  of  an  inch  : the  sar- 
torius,  or  tailor’s  muscle,  by  which  the  legs  are  crossed, 
arises  on  the  top  of  the  hip  bone,  and  extends  six  inches 
below  the  knee,  passing  two  joints, — being  nearly  three 
feet  long.  On  the  back,  the  latissimus  dursi,  by  which 
the  hand  is  brought  downward  and  backward,  as  by  a 
blacksmith  in  using  a hammer,  is  a foot  broad  on  the 
back,  scarcely  an  inch  in  width  at  its  attachment  to 
the  arm,  below  the  shoulder,  but  all  of  two  feet  in 
length. 

All  muscles,  are  large  in  the  middle,  but  small  at  the 
extremities  : — each  one,  too,  is  enveloped  in  a sheath,  to 
keep  it  separate  from  a contiguous  one,  that  the  action 
may  not  interfere  with  the  assigned  office  of  any  other. 
Indeed,  each  bundle  of  fibres  of  which  the  muscle  is  com- 
posed, is  secured  in  a sheath  of  its  own,  and  the  whole 
are  finally  encased  in  the  outside  tissue,  that  binds  down 
and  secures  the  whole. 

These  coverings  of  the  muscles  are  elastic,  stretching 


ANATOMICAL  CUSS  BOOK. 


53 


and  recovering  their  original  form  when  the  contents  are 
relaxed.  When  the  greatest  degree  of  contraction  takes 
place,  as  in  the  muscles  of  the  thigh,  the  power  of  the 
muscle  is  increased  a hundred  fold  by  the  tightness  of 
the  fascia.  On  the  arm,  for  example,  between  the  elbow 
and  shoulder,  the  flexor  of  the  fore  arm,  in  a state  of 
action,  produces  a very  prominent  ball  near  the  middle 
of  the  bone:  on  the  inferior  extremities,  were  the  muscles 
to  project  out  in  such  a manner,  all  symmetry  would  inevi- 
tably be  sacrificed,  and  the  power  too,  would  be  very 
much  abridged.  Laborers  bind  a cord  round  the  arm 
when  they  wish  to  exert  an  extraordinary  degree  of 
strength  : — sailors,  too,  in  order  to  increase  their  muscu- 
lar power,  usually  wear  a tightly  girded  leather  belt  just 
above  the  hips,  — the  principle  of  which  is  to  bind  down 
the  bellies  of  the  muscles,  more  closely  than  the  straps 
which  nature  has  placed  over  them. 

The  muscles  are  divided  into  two  classes,  viz  : the  vol- 
untary, and  involuntary ; the  first  are  subservient  to  the 
will ; but  the  second  order  is  wholly  beyond  its  influence. 
To  put  the  voluntary  muscles  in  action,  we  have  only  to 
will  it;  to  incline  the  power  to  effect  an  orderly  contrac- 
tion. It  is  only  necessary  to  will  the  bending  of  a finger, 
and  it  is  done  — to  will  the  clenching  of  the  hand,  and 
the  action  follows  instantly  ; to  flex  the  leg,  or  extend  the 
foot,  and  the  command  of  the  brain  is  obeyed. 

On  the  other  hand,  the  muscular  fibres  of  the  stomach 
are  independent  of  the  mind  : the  ear  receives  sonorous 
rays,  and  propagates  them  to  the  labyrinth,  by  the  com- 
bined muscular  apparatus  within,  nor  can  we  prevent  it 
by  any  effort  of  the  mind  to  the  contrary. 

Before  muscles  become  orderly  — before  they  can  serve 
the  mind,  they  must  be  taught.  Thus  the  child  is  obliged 

5* 


54 


ANATOMICAL  CLASS  BOOK 


to  totter  round  the  room,  receiving  severe  falls,  before  the 
muscles  become  trained  to  the  business  for  which  they 
were  designed.  The  infant  that  has  crept,  feels  safer  on 
its  hands  and  knees,  than  on  its  feet,  because,  by  prac- 
tice, the  locomotive  muscles  obey  the  child  in  that  posi- 
tion, and  it  is  conscious  of  its  security,  from  its  recollection 
of  the  fact. 

When  the  child  first  endeavors  to  maintain  an  erect 
posture,  its  step  is  insecure,  the  muscles  not  having 
been  associated  to  act  in  the  new  trial ; the  positive  influ- 
ence of  mind,  therefore,  must  not  be  suspended  an  in- 
stant; if  it  is,  the  infant  falls  to  the  floor. 

When,  therefore,  any  number  of  muscles  have  had 
practice  in  any  particular  mode  or  time,  a habit  is  ulti- 
mately established,  enabling  them  to  continue  the  accus- 
tomed motion,  without  the  watchful  efforts  of  the  mind. 
It  is  in  this  way  that  we  learn  to  walk,  to  articulate  words, 
to  rise,  to  sit,  or  assume  a daily  multitude  of  positions. 

The  principal  difficulty  the  young  musician  has  to  en- 
counter in  learning  to  play  an  instrument,  consists  in 
teaching  the  muscles  of  the  fingers  to  move  as  rapidly  as 
the  notes  are  presented  by  the  brain.  Hence  the  long 
practice  required,  before  rapid  execution  is  attained.  By  a 
long  course  of  schooling,  the  player  can  at  length  partially 
withdraw  the  mental  superintendence, — he  can  slumber, 
or  abstract  his  thoughts  from  the  air,  or  enter  into  conver- 
sation, but  the  fingers  continue  their  unerring  course,  in 
time  and  with  surprising  accuracy. 

The  most  opposite,  and  apparently  incongruous  associ- 
ations of  muscular  action,  are  exhibited  by  rope-dancers, 
in  throwing  carving-knives,  which  fall  in  a perfect  line, 
points  downward,  toward  the  crown  of  the  head,  while 
heavy  brass  rings  are  whirled  with  extreme  rapidity  in  op- 
posite directions,  on  each  of  the  great  toes.  Such  exam- 
ples of  the  extraordinary  feats  that  may  be  accomplished 


ANATOMICAL  CLASS  BOOK. 


55 


by  teaching  muscles  to  act  differently  from  what  they  ap- 
pear to  have  been  expressly  intended,  are  exceedingly 
common,  but  not  the  less  surprising. 

It  must  not  be  lost  sight  of  that  the  two  orders  of  mus- 
cles are  obedient  to  their  proper  rulers ; the  one  being 
under  the  express  dominion  of  the  mind,  and  the  other 
influenced  only  by  its  appropriate  stimulus.  Food  is  the 
natural  excitant  of  the  muscular  tissue  of  the  stomach, 
and  the  blood,  by  its  presence,  stimulates  the  fibres  of  the 
heart. 

But  the  most  perplexing  circumstance  in  relation  to 
the  muscles,  is  the  property  of  contraction.  Every  mus- 
cle in  the  body  is  always  tense  ; relaxation  is  a misapplied 
expression,  if  it  were  understood  that  the  rest  of  the 
muscle  is  like  a rope  slacked  till  it  becomes  pendulous 
between  two  points  of  attachment.  However  much  a 
joint  may  be  bent,  the  muscles  always  remain  tense  ; ap- 
parently as  much  so,  as  when  actually  put  upon  the  stretch 
by  the  extension  of  the  same  joint.  They  carry  their 
contraction  still  further  in  cases  of  luxations. 

When  the  hip  joint  is  dislocated,  the  muscles  of  the 
thigh,  finding  nothing  to  oppose  them,  shorten  the  limb  by 
inches,  and  hold  their  grasp  so  tenaciously  that  pulleys  are 
required  to  overcome  their  unrestrained,  unauthorized 
activity. 

When  the  joint  has  been  too  long  neglected,  and  the 
head  of  the  bone  cannot  be  carried  back  to  the  socket,  on 
account  of  the  violent  rigidity  of  the  surrounding  muscles, 
they  invariably  continue  in  that  condition  through  life. 
Such  a limb  is  consequently  thicker  than  its  fellow,  the 
circumference  being  gained  at  the  expense  of  its  length. 

Muscles  are  never  10 ear y — no,  never,  under  any  cir- 
cumstances whatever  ; if  that  were  possible,  there  would 
be  examples  of  their  inability  to  answer  the  requirements 
of  the  will,  from  this  cause.  The  mind’s  control  over 


56 


ANATOMICAL,  CLASS  BOOK. 


them  may  be  suspended  or  even  lost,  as  will  be  shown 
directly,  but  still  they  are  always  active,  and  always  in  a 
state  of  contraction.  If  their  irritability  were  reduced 
by  fatigue,  it  could  not  be  recalled  ; the  vis  insita,  the 
life  of  the  muscle,  survives  the  departure  of  the  soul,  and 
keeps  it  in  a moderate  contraction  long  after  the  vital  tem- 
perature has  been  lost. 

Nothing,, indeed,  short  of  putrefaction,  destroys  its  con- 
tractility. Death,  by  which  is  meant  the  separation  of  the 
spiritual  essence  from  the  material  body,  does  not  destroy, 
suddenly,  the  life  of  the  flesh,  as  that  survives  for  days  and 
even  weeks.  The  truth  of  this  position  is  established  by 
the  application  of  galvanism  to  the  bodies  of  malefactors 
— the  rolling  eye-balls,  the  cramped  limbs,  the  heaving 
chest,  and  in  the  fiendish  expression  of  the  muscles  of 
the  face. 

An  illustration  of  the  permanency  of  this  irritability 
may  be  seen  also  in  the  quivering  meat  hung  up  in  the 
shambles  of  the  market;  it  is  exhibited  in  the  writhings 
of  the  eel  deprived  of  its  head  and  its  skin ; and  in  the 
violent  snapping  of  the  tortoise’s  jaws,  many  days  after 
decapitation. 

When  we  are  perfectly  exhausted,  by  reason  of  long 
continued  fatigue,  the  muscles  are  not  the  sufferers  ; they 
then  show  their  activity  by  violent  exertions.  Cramps, 
severe  paroxysms,  and  painful  contractions,  at  such  times 
supervene,  and  rarely  at  any  other.  These  arise  from  the 
loss  of  the  nervous  power , which  is  the  regulator  of  the 
system. 

That  power  may  be  diminished  by  long  continued  ex- 
ercise, by  extreme  watchfulness,  or  by  many  other  causes. 
Yet  while  it  is  feeble,  the  muscles  twitch,  and  permanent 
distortions  ensue,  if  the  nerves  do  not  recover  their  ener- 
gy. We  retire  to  our  beds,  not  to  give  the  muscles  an 
opportunity  of  reposing,  but  to  recover  nervous  influence. 


ANATOMICAL  CLASS  BOOK. 


57 


Every  muscle  has  an  antagonist,  with  a few  exceptions. 
Where  there  is  one  to  draw  in  one  direction,  there  is  an 
opponent  to  counteract ; by  this  contrivance,  a complete 
freedom  of  motion  is  given  to  the  extremities.  Each 
flexor  has,  opposed  to  it,  an  extensor  ; and  the  contraction 
of  one,  is  partially  accomplished  by  the  relaxation  of  the 
other ; but  the  simultaneous  action  of  both,  fixes  the  part 
on  which  they  exert  their  power  ; thus,  the  flexors  on  the 
fore  part  of  the  neck,  and  their  antagonists  on  the 
back  side,  maintain  the  head  in  a vertical  line  with  the 
body. 

Each  muscle  terminates  in  a hard,  white  cord,  appa- 
rently the  compressed  threads  constituting  its  volume,  al- 
though such  is  not  the  fact.  These  are  called  tendons. 

At  the  place  of  origin,  the  tendon  is  thin,  inelastic,  and 
short,  soon  intermingling  itself  with  the  substance  of  the 
muscle  ; but  at  the  other  end  it  assumes  another  form, 
being  either  round,  or  delicately  smooth,  tape-like  and 
narrow.  This  is  the  part  which  passes  over  a joint  to  be* 
come  attached  to  the  next  bone.  Tendons  are  nearly  in* 
sensible,  being  so  far  removed  from  the  ordinary  sensibil- 
ity of  everything  else,  that  they  rarely  participate  in  the 
diseases  to  which  all  the  soft  portions  of  the  frame  am 
subject. 

To  obviate  friction,  and  prevent  interference  with  its 
neighbors,  each  tendon  is  invariably  conducted  through  a 
sheath,  in  which  there  is  a copious  secretion  of  a fluid, 
resembling  oil,  that  keeps  the  cord  soft,  that  it  may  glide 
easily. 

Symmetry  of  form  is  wholly  referable  to  the  tendons. 
Without  them,  the  exceeding  bulk  of  the  muscle  would 
produce,  according  to  our  present  notion  of  the  beautiful, 
the  most  hideous  deformities. 

Were  the  muscles  of  the  fore  arm  carried  to  the  palm, 
of  the  same  size  that  they  have  at  the  elbow,  the  wrist 


5$ 


ANATOMICAL  CLASS  BOOK. 


would  be  the  diameter  of  the  elbow — rendering  the  hand 
unwieldy  and  nearly  useless. 

To  the  free  circulation  of  the  blood  into  its  inmost  re- 
cesses, the  muscle  is  indebted  for  its  vigor;  and  to  the 
nerves,  for  that  sensitiveness  which  renders  it  susceptible 
of  painful  or  pleasurable  sensations. 

In  its  constitution,  however,  the  muscle  possesses  a 
sensibility,  completely  beyond  the  control  of  any  nerves  in 
the  body  ; a curious  circumstance  indeed,  referred  to  in 
speaking  of  its  vis  insita.  An  exhibition  of  this  proper- 
ty — this  disposition  to  recoil  under  excitement ; to  remove 
itself  from  the  contact  of  foreign  substances  ; in  short,  to 
preserve  itself  from  the  destructive  agency  of  whatever 
has  a tendency  to  exhaust  its  latent  irritability,  is  within 
common  reach.  A demonstration  of  this  phenomenon 
may  be  witnessed  in  the  hearts  of  reptiles,  pulsating  by 
the  prick  of  a pin,  long  after  being  removed  from  the  ani- 
mal; in  the  motion  of  the  intestines  of  cats  and  dogs,  cut 
into  strips.  While  the  vital  temperature  remains,  they 
move  like  earth-worms,  and  when  they  have  ceased  to 
move,  their  irritability  can  be  roused  again  by  the  applica- 
tion of  stimuli. 

Here,  then,  is  exemplified  the  existence  of  a property, 
purely  vital,  which  never  was,  and  irt  the  instance  before 
us,  could  not  be  influenced  by  the  nervous  system. 

Removed  as  this  property  is,  from  the  direct  influence 
of  the  nerves,  it  becomes,  under  peculiar  circumstances, 
the  only  hope.  In  cases  of  suspended  animation,  as  in 
drowning,  swooning,  &c,  there  is  a prostration  of  the 
nervous  system  — it  cannot  act  — the  will  cannot  produce 
an  impression  on  the  muscles,  because  its  messengers,  the 
nerves,  are  no  longer  in  a condition,  from  some  unknown 
cause,  to  transmit  the  orders.  At  this  juncture,  if  no 
saving  efforts  are  made,  the  individual  dies.  But  a skil- 


ANATOMICAL  CLASS  BOOK. 


59 


ful  application  of  agents  to  the  muscles,  raises  their  tone 
to  that  high  degree  of  excitability,  that  they  actually  re- 
suscitate the  expiring  spirit  of  the  nerves.  The  instant 
that  is  effected,  the  sign  of  success  is  manifested  by 
the  obedience  of  the  muscles;  the  poor  sufferer  moves  a 
limb,  because  he  determines  it;  order  is  at  the  same  in- 
stant restored  in  the  nerves,  and  the  sufferer  is  restored 
to  life,  and  his  weeping  friends  to  happiness. 


A CATALOGUE  OF  THE  PRINCIPAL  MUSCLES. 

Perhaps  it  may  be  thought  that  the  following  table  is 
not  only  unnecessarily  minute,  but  altogether  too  techni- 
cal; but  as  we  could  devise  no  method  of  rendering  it 
much  more  simple,  without  making  the  whole  unintelligi- 
ble,— the  scientific  names  of  the  points  of  origin  and  in- 
sertion, have  been  preserved.  It  is  not  expected  that 
children  will  either  be  interested  or  required  to  learn  this 
intricate  division  of  anatomy,  even  should  the  first  prin- 
ciples of  the  science  be  generally  taught  in  common 
schools. 

For  instructors,  however,  drawing-school  pupils  and 
young  artists,  the  few  technical  words  which  are  retained, 
will  be  of  consequence,  as  they  will  be  able  to  refer  to  the 
skeleton,  (which  we  also  hope  will  be  considered,  at  no 
very  remote  period,  an  indispensable  part  of  school  appa- 
ratus,) for  the  exact  places  to  which  they  refer. 


Note.  — Where  the  muscle  has  no  fellow,  it  is  marked 
thus.  * It  should  be  recollected  that  the  muscles  of  one  side 
of  the  body  only,  are  here  considered. 


60 


ANATOMICAL  CLASS  BOOK. 


M USCLE3  OF  THE  HEAD,  EYELIDS,  EYEBALL,  NOSE  AND  MOUTH. 


Name.  Arises  from 

Occipito-frontalis.*  The  upper  ridge  of  the  oc- 

cipital bone ; its  aponeurosis 
covers  the  upper  part  of  the 
head. 

Corrugator  supercilii.  Above  the  root  of  the  nose. 


Orbicularis  palpebrarum. 

Levator  palpebrae  superi- 
oris. 

Rectus  superior.  } 
Rectus  inferior.  f 
Rectus  internus.  t 
Rectus  externus.  j 
Obliquus  superior,  or  Tro- 
chlearis. 


Obliquus  inferior. 


Around  the  edge  of  the 
orbit. 

The  bottom  of  the  orbit 
near  the  optic  foramen. 

Around  the  optic  foramen 
of  the  sphsenoid  bone,  at  the 
bottom  of  the  -orbit. 

Near  the  optic  foramen,  and 
passes  through  a loop  in  the 
internal  canthus  of  the  eye, 
and  is  reflected  to  be 

The  ductus  nasalis,  and  is 
inserted 


Fig  31. 


Explanation  of  Fig. 
31. 

a,  the  pyramidalis 
nasi;  o,  the  com- 
pressor nasi;  a,  oc- 
cipito  frontalis ; c, 
orbicularis  palpe- 
brarum; p,  corruga- 
tor supercilii ; n,  le- 
vator palpebrce  supe- 
rioris  ; f,  zygomati- 
cus  major ; e,  zygo- 
maticus  minor ; i, 
orbicularis  oris  ; k, 
depressor  anguii  or- 
is ; m,  depressor  la- 
bii  inferioris  ; h,  the 
masseter  muscle  ; g, 
the  buccinator ; d. 
levator  labiisuperio- 
sis  alteque  nasi ; g, 
the  parietal  bone 
seen  beyond  the  cor- 
onal suture. 


m 


ANATOMICAL  CLASS  EOOR. 


61 


MUSCLES  OF  THE  HEAD,  EYELIDS,  EYEBALL,  NOSE  AND  MOUTH. 


Inserted,  into 

The  skin  of  the  eyebrows 
and  root  of  the  nose. 

The  inner  part  of  the  occi- 
pito-frontalis. 

The  inner  corner  of  the 
eyes. 

The  cartilage  of  the  tarsus 
of  the  upper  eyelid. 

The  anterior  part  of  the 
tunica  sclerotica,  opposite  to 
each  other. 

The  posterior  part  of  the 
bulb,  between  the  rectus  and 
the  entrance  of  the  optic  nerve. 


Use. 

To  pull  the  skin  of  the  head 
backward  — raise  the  eye- 
brows and  skin  of  the  fore- 
head. 

To  wrinkle  the  eyebrows. 

To  shut  the  eye. 

To  open  the  eye,  by  raising 
the  upper  eyelid. 

To  raise  it  upward. 

To  pull  it  downward. 

To  turn  it  to  the  nose. 

To  move  it  outward. 

To  roll  the  eye,  and  turn 
the  pupil  downward  and  out- 
ward. 


Opposite  to  the  former.  To  roll  the  eye. 


By  recurring  to  the  plate,  (Fig.  31,)  the  pupil  will  form  a tolera 
bly  accurate  idea  of  the  muscles  of  the  face.  They  lie  very  super- 
ficially, just  under  the  skin,  and  are  all  muscles  of  expression  ; 
therefore  only  perfectly  developed  in  the  European,  or  white  man’s 
face,  in  whose  countenance  the  passions  of  the  mind  arc  strongly 
exhibited.  In  the  negro,  owing  partly  to  the  color  of  the  skin,  the 
expression  is  necessarily  very  imperfect:  — he  can  never  have  maj- 
esty nor  dignity,  or  an  elevation  of  thought,  portrayed  in  his  fea- 
tures. When  the  jet  black  negro  expresses  his  emotions,  — unless 
the  teeth,  and  the  whites  of  the  eyes  are  exposed,  — there  is  little  va- 
riety of  expression,  because  no  shades  are  created  by  the  contrac- 
tions of  the  muscles.  This  fact  is  familiar  to  artists, — to  the  en- 
graver and  the  painter.  The  pictures  of  colored  persons  are  always 
very  nearly  alike  ; the  portrait  of  one,  indeed,  will  answer  for 
many,  — and  the  circumstance  is  wholly  referable  to  the  imperfect 
manner  in  which  the  light  and  shadows  are  created  on  the  skin. 

The  muscles  of  expression  are  fewer  and  smaller,  as  animals  de- 
scend the  scale  of  creation. 


6 


62 


ANATOMICAL  CLASS  IIOOK. 


Name. 

Levator  labii  superions 
alseque  nasi. 

Levator  labii  superioris  pro- 
prius. 

Levator  anguli  oris. 
Zygomaticus  major. 

Zygomaticus  minor. 
Buccinator. 


Depressor  anguli  oris. 
Depressor  labii  inferioris. 


Arises  from 

The  nasal  process  of  the 
superior  maxillary  bone. 

The  upper  jaw,  under  the 
orbit. 

Tbe  orbitar  foramen  of  the 
sup.  max.  bone. 

The  os  jugale,  near  the 
zygomatic  suture,  and  runs 
downward. 

Above  the  zygomaticus  ma- 
jor. 

The  sockets  of  the  last  mo- 
lares,  and  the  coronoid  pro- 
cess of  the  lower  jaw. 

The  lower  edge  of  the  un- 
der jaw,  near  the  chin. 

The  inferior  part  of  the 
lower  jaw,  next  the  chin. 


Fig.  32. 


ANATOMICAL  CLASS  BOOK. 


6:J 


Inserted  into 

The  upper  lip  and  ala  of 
the  nose. 

The  middle  of  the  upper 
lip. 

The  orbicularis,  at  the  an- 
gle of  the  mouth. 

The  angle  of  the  mouth, 
with  the  depressor  of  the  lip. 


Use. 

It  raises  the  upper  lip,  and 
dilates  the  nostrils. 

To  pull  the  upper  lip  di- 
rectly upward. 

To  raise  the  corner  of  the 
mouth. 

To  inflate  the  cheek  and 
raise  the  angle  of  the  mouth. 


The  angle  of  the  mouth. 

The  angle  of  the  mouth, 
and  is  perforated  by  the  duct 
■of  the  parotid  gland. 

The  angle  of  the  mouth. 

The  middle  of  the  under  lip. 


To  raise  the  angle  of  the 
mouth  outward. 

To  contract  the  mouth,  and 
draw  the  angle  of  it  outward 
and  backward. 

To  draw  the  corner  of  the 
mouth  downward. 

To  draw  the  under  lip  down- 
wardand  outwar  d. 


Explanation  of  Fig.  32. 

d.  The  occipitofrontalis. 

e.  The  orbicularis  palpebrarum. 

f.  The  corrugator  supercilii. 

g.  The  compressor  naris. 

h.  The  orbicularis  oris. 

i.  The  levator  labii  superioris  alaeque  nasi. 

j.  The  levator  anguli  oris. 

k.  The  zygomaticus  major  and  minor. 
t.  The  depressor  anguli  oris. 

>n.  The  depressor  labii  inferioris, 

n.  The  buccinator. 

o.  The  masseter. 

p.  The  temporal  fascia,  or  aponeurosis. 

2.  The  parotid  gland,  which  supplies  the  mouth  with  saliva. 

3.  Steno’s  duct,  to  conduct  the  fluid  into  the  mouth. 

4.  The  temporal  artery. 

5.  The  facial  artery. 

Farts  seen  in  the  neck. 

q.  The  sterno-cleido  mastoideus. 

r.  The  omo-hyoideus. 

s.  The  sterno-hyoideus. 

t.  The  sternothyroideus. 
m.  The  digastricus. 

v.  The  stylo-hyoideus. 

The  mylo-hyoideus. 

6.  The  submaxillary  gland , — also  pours  saliva  into  the  mouth. 

7.  The  external  jugular  vein. 

S.  The  sheath  containing  the  carotid  artery. 


(54 


ANATOMICAL  CLASS  BOOK. 


Name. 

Orbicularis  oris.* 


Depressor  labii  superions 
aleque  nasi. 

Constrictor  nasi. 

Levator  menti  vel  labii  in- 
ferioris. 

MUSCLES  OF  THE 

Superior  auris,  or  attoliens 
aurem. 

Anterior  auris. 

Posterior  auris,  or  retrahens 
auris. 

Helicis  major. 

Helicis  minor. 

Tragicus. 

Antitragus. 

Transversus  auris. 

' MUSCLES  OF  THE 

Laxator  tympani. 

Tensor  tympani. 

Stapedius. 


Arises  from 

This  muscle  surrounds  the 
lips,  and  is  in  a great  measure 
formed  by  the  buccinator,  zy- 
gomatici,  and  others,  which 
move  the  lip. 

The  sockets  of  the  upper 
incisor  teeth. 

The  root  of  one  wing  of  the 
nose,  and 

Tire  lower  jaw,  at  the  root 
of  the  incisors. 

EXTERNAL  EAR. 

The  tendon -of  the  occipito- 
frontalis above  the  ear. 

Near  the  back  part  of  the 
zygoma. 

The  mastoid  process,  by 
two  and  sometimes  three  fas- 
ciculi. 

The  upper,  anterior,  and 
acute  part  of  the  helix. 

The  interior  and  anterior 
part  of  the  helix. 

The  outer  and  middle  part 
of  the  concha,  near  the  tragus. 

From  the  root  of  the  inner 
part  of  the  helix. 

The  upper  part  of  the  con- 
cha. 

INTERNAL  EaR. 

The  spinous  process  of  the 
sphienoid  bone. 

The  cartilaginous  extremity 
of  the  Eustachian  tube. 

A little  cavern  in  the  pe- 
trous portion,  near  the  cells 
of  the  mastoid  process. 


ANATOMICAL  CLASS  BOOK. 


65 


Inserted  into 


The  root  of  the  ala  nasi  and 
upper  lip. 

goes  across  to  the  other. 

The  skin  in  the  centre  of 
the  chin. 

MUSCLES  OF  THE 

The  root  of  the  cartilagi- 
nous tube  of  the  ear. 

The  eminence  behind  the 
helix. 

The  septum  that  divides  the 
scapha  and  concha. 

The  cartilage  of  the  helix, 
a little  above  the  tragus. 

The  crus  of  the  helix. 

The  upper  part  of  the  tra- 
gus. 

The  upper  part  of  the  anti- 
tragus. 

The  inner  part  of  the  helix. 


MUSCLES  OF  THE 

The  long  process  of  the 
malleus. 

The  handle  of  the  malleus. 


The  posterior  part  of  the 
head  of  the  stapes. 

6* 


Use. 

To  shut  the  mouth,  by  con- 
tracting the  lips. 


To  pull  the  ala  nasi  and 
upper  lip  down. 

To  compress  the  wings  of 
the  nose. 

To  raise  the  under  lip  and 
skin  of  the  chin. 

EXTERNAL  EAR. 

To  draw  the  ear  upward, 
and  make  it  tense. 

To  raise  this  eminence  for- 
ward. 

To  draw  the  ear  back,  and 
stretch  the  concha. 

To  depress  the  upper  part 
of  the  helix. 

To  contract  the  fissure. 

To  depress  the  concha,  and 
pull  the  tragus  a little  out- 
ward. 

To  dilate  the  mouth  of  the 
concha. 

To  draw  these  parts  toward 
each  other. 


INTERNAL  EAR. 

To  draw  the  malleus  ob- 
liquely forward,  toward  its 
origin. 

To  pull  the  malleus  and 
membrane  of  the  tympanum 
toward  the  petrous  portion. 

To  draw  the  stapes  oblique- 
ly upward  toward  the  cavern. 


m 


ANATOMICAL  CLASS  BOOK. 


MUSCLES  OF  THE  LOWER  JAW. 


Name.  • 
Temporalis. 


Masseter. 


Pterygoideus  internus. 
Pterygoideus  externus. 


./Irises  from 

The  lower  part  of  the  pari- 
etal bone  and  os  frontis ; 
squamous  part  of  the  tempo- 
ral bone  : back  part  of  the  os 
jugale  ; the  temporal  process 
of  the  sphsenoid  bone,  and  the 
aponeurosis  which  covers  it. 

The  sup.  max.  bone,  near 
the  os  jugale;  and  from  the 
anterior  part  of  the  zygoma. 

The  internal  pterygoid  pro- 
cess of  the  sphtenoid  bone. 

The  external  pterygoid  pro- 
cess. 


MUSCLES  ABOUT  THE  NECK. 

Platysma  myoides.  The  cellular  membrane  cov- 

ering the  pectoral  and  deltoid 
muscles. 

Sterno-cleido-mastoideus.  The  upper  part  of  the  ster- 
num, and  fore  part  of  the  clav- 
icle. 


Fig.  33. 


ANATOMICAL  CLASS  BOOK. 


67 


muscles  of  the  lower  jaw. 


Inserted  into 

The  coronxnd  process  of  the 
lower  jaw,  its  fibres  being' 
bundled  together  and  pressed 
into  a small  compass,  so  as  to 
pass  under  the  jugum,  or  zyg- 
oma. 

The  angle  of  the  lower  jaw 
upwards  to  the  basis  of  the 
corOnoid  process. 

The  lower  jaw  on  its  inner 
side,  and  near  its  angle. 

The  condyloid  process  of 
the  lower  jaw  and  capsular 
ligament. 


Use. 

To  move  the  lower  jaw  up 
ward. 


To  raise  and  move  the  jaw 
a little  forward  and  back- 
ward. 

To  raise  the  lower  jaw,  and 
draw  it  a little  to  one  side. 

To  move  the  jaw,  and  to 
prevent  the  ligament  of  the 
jaw  from  being  pinched. 


MUSCLES  ABOUT  THE  NECK. 


The  side  of  the  chin  and 
integuments  of  the  cheek. 


To  draw  the  cheeks  and  skin 
of  the  face  downward. 


The  mastoid  process,  and  as  To  move  the  head  to  one 
far  back  as  the  occipital  su-  side  and  bend  it  forward, 
ture. 

Explanation  of  Fig.  33. 

A,  and  b.  sterno  cleido  mastoid eus  ; h.  stylo  hyoidens  ; g,  g,  the 
two  bellies  of  the  digastricus  ; f,  sterno  hyoidens  ; i,  the  lower  end 
of  the  mastoideus  ot  the  right  side;  e,  omo  hyoidens;  d,  the  09 
hyoides ; c,  the  clavicle;  k,  complexus. 

Under  the  sterno  cleido  mastoid  muscle,  bounded  by  the  letters  a 
and  b,  in  the  opposite  drawing,  are  a vaiiety  of  b<  aulilul,  libbon- 
like  muscles,  which  are  generally  attached  to  the  bone  of  the 
tongue,  and  the  vocal  box, — called  the  larynx , which  is  the  protu- 
berance in  the  front  part  of  the  throat.  Again,  those  muscles  which 
arise  about  the  base  of  the  skull,  under  the  ear,  and  angle  of  the 
under  jaw,  are  also  inserted  into  the  same  places, — so  that  the  bone 
and  larynx  are  moveable  fulcrums,  — increasing  the  power  of  the 
muscles  on  cither  side,  by  changing  their  position.  By  this  simple 
contrivance,  the  contraction  of  the  muscles  compress  the  windpipe, 
and  thus  increase,  or  vary  the  tone  of  the  voice,  by  diminishing  the 
diameter  of  the  air  tube.  Thus,  bad  singers  in  sounding  a high  note 
stretch  back  the  head  ; thus,  too,  unconsciously  press  the  musical 
pipe  into  the  smallest  diameter.  To  sound  a bass  note,  the  chin  is 
brought  towards  the  bi east, — and  the  same  muscles  are  relaxed, 
and  the  diameter  of  the  tube  is  at  once  ir.cieased. 


63 


ANATOMICAL  CLASS  BOOK. 


MUSCLES  SITUATED  BETff] 

OF  T 

Name. 

Digastricus. 

Mylo-hyoideus. 

Genio-hyoideus. 

Genio-glossus. 

Hyo-glossus. 

Lingualis. 

MUSCLES  SITUATED  BETWEEN 

Sterno-hyoideus. 

Omo-hyoideus. 

Sterno-thyroideus. 

Thyreo-hyoideus,  or  Ilyo- 
thyroideus. 

Crico-thyroideus. 


THE  LOWER  JAW  AND  BONE 
TONGUE. 

Arises  from 

A fossa  at  the  root  of  the 
mastoid  process. 

The  inner  surface  of  the 
jaw  bone. 

The  inside  of  the  chin. 

The  inside  of  the  chin. 

The  horn,  basis,  and  carti- 
lage of  the  os  hyoides. 

The  root  of  the  tongue  lat- 
erally. 

THE  os  HYOIDES  AND  TRUNK. 

The  sternum  and  clavicle. 

Near  the  coracoid  process 
of  the  scapula. 

The  upper  and  inner  part  of 
the  sternum. 

Part  of  the  basis  and  horn 
of  the  os  hyoides. 

The  side  of  the  cricoid 
cartilage. 


MUSCLES  SITUATED  BETWEEN  THE  LOWER  JAW  AND  OS 


HYOIDES, 

Stylo-glossus. 

Stylo-hyoideus. 

Stylo-pharyngeus. 

Circumflexus, 

or 

Tensor  palati. 

Levator  palati  mollis. 


LATERALLY. 

The  apex  of  the  styloid 
process. 

The  basis,  and  about  the 
middle  of  the  styloid  process. 

The  root  of  the  styloid  pro- 
cess. 

Near  the  Eustachian  tube, 
and  passes  through  the  hamu- 
lus of  the  pterygoid  process, 
to  be 

The  point  of  the  os  petros- 
um,  the  Eustachian  tube,  and 
sphsenoid  bone. 


ANATOMICAL  CLASS  BOOK. 


69 

MUSCLES  SITUATED  BETWEEN  THE  LOWER  JAW  AND  BONE 
OF  THE  TONGUE. 


Inserted,  into 

The  lower  and  anterior  part 
of  the  chin. 

The  basis  of  the  os  hyoides. 

The  basis  of  the  os  hyoides. 

The  tongue,  forming  part 
of  its  substance. 

Into  the  tongue  laterally. 

The  extremity  of  the  tongue. 


Use. 

To  draw  the  lower  jaw 
downward. 

To  move  the  os  hyoides  up- 
ward. 

To  move  the  os  hyoides  up- 
ward. 

To  move  the  tongue  in  va- 
rious directions. 

To  draw  the  tongue  down- 
ward and  inward. 

To  shorten  and  draw  the 
tongue  backward. 


MUSCLES  SITUATED  BETWEEN 

The  basis  of  the  os  hyoides. 

The  basis  of  the  os  hyoides. 

The  thyroid  cartilage. 

The  side  of  the  thyroid  car- 
tilage. 

The  inferior  horn  of  the 
thyroid  cartilage. 


THE  OS  HYOIDES  AND  TRUNK. 

To  draw  the  os  hjoides 
downward. 

To  draw  the  os  hyoides 
downward. 

To  pull  the  thyroid  cartilage 
downward. 

To  raise  the  cartilage,  and 
depress  the  bone. 

To  pull  the  thyroid  cartil- 
age towards  the  cricoid. 

os 


MUSCLES  SITUATED  BETWEEN  THE  LOWER  JAW  AND 
HYOIDES,  LATERALLY. 


The  side  of  the  root  of  the 
tongue. 

The  basis  of  the  os  hyoides. 

The  edge  of  the  pharynx, 
and  back  of  the  thyroid  carti- 
lage. 

The  velum  pendulum  pal- 

ati. 


To  pull  the  tongue  back- 
ward. 

To  draw  the  os  hyoides  up- 
ward. 

To  dilate  the  pharynx,  and 
raise  the  cartilage. 

To  draw  the  velum  pendu- 
lum palati  obliquely  down- 
ward, and  stretch  it. 


The  velum  pendulum  pal- 
ati, being  expanded  upon  it. 


To  pull  the  velum  pendu- 
lum backward  and  upward. 


70 


ANATOMICAL  CLASS  BOOK. 


MUSCLES  SITUATED  ABOUT  THE  ENTRY  OF  THE  FAUCES. 


Name. 

Constrictor  faucium. 


Palato-Pharyngeus. 


Azygos  uvulae.* 


Jl  rises  from 

Near  the  root  of  the  tongue, 
on  each  side,  and  goes  round 
to  be 

The  middle  of  the  soft 
palate,  goes  round  the  entry 
of  the  fauces,  the  tendon  of 
the  circumflexus  palati,  and 
velum  pendulum  palati,  to  be 

The  commissure  of  the  ossa 
palati. 


MUSCLES  SITUATED  ON  THE  POSTERIOR  PART  OF  THE  PHARYNX. 


Constrictor  pharyngius  infe- 
rior. 

Constrictor  pharyngius  me- 
dius. 

Constrictor  pharyngius  su- 
perior. 


The  cricoid  ar.d  thyroid 
cartilages. 

The  horns,  and  appendix  of 
the  os  hyoides. 

The  pterygoid  process,  the 
lower  jaw,  and  the  cuneiform 
process  of  the  os  occipitis. 


MUSCLES  SITUATED  ABOUT  THE  GLOTTIS. 


Crico-arytenoideus  posti- 
cus. 

Crico-arytiEnoideus  later- 
alis, or  obliquus. 

Thyreo-arytenoideus. 

Arytenoideus  obliquus.* 

Arytenoideus  transversus.* 

Thyreo-epiglottideus. 

Aryteno-epiglottideus. 


The  cricoid  cartilage  poste- 
riorly. 

The  side  of  the  cricoid  car- 
tilage. 

The  back  of  the  thyroid 
cartilage. 

The  root  of  one  arytenoid 
cartilage- 

One  of  the  arytenoid  car- 
tilages. 

The  thyroid  cartilage. 

The  upper  part  of  the  ary- 
tenoid cartilage  laterally. 


ANATOMICAL  CLASS  BOOK. 


71 


MUSCLES  SITUATED  ABOUT  THE  ENTRY  OF  THE  FAUCES. 


Inserted  into 

The  middle  of  the  velum 
pendulum  palati,  near  the 
uvula. 

The  upper  and  posterior 
part  of  the  thyroid  cartilage. 


The  extremity  of  the  uvula. 


Use. 

To  raise  the  tongue,  and 
draw  the  velum  toward  it. 

To  contract  the  arch  of  the 
fauce. 


To  shorten  and  raise  the 
uvula. 


MUSCLES  SITUATED  ON  THE  POSTERIOR  PART  OF  THE  PHARYNX. 


The  middle  of  the  pharynx. 
The  ambit  of  the  pharynx. 

The  middle  of  the  pharynx. 


MUSCLES  SITUATED 

The  back  of  the  arytienoid 
cartilage. 

The  side  of  the  arytenoid 
cartilage. 

The  fore  part  of  the  aryte- 
noid cartilage. 

The  extremity  of  the  other. 

The  other  arytenoid  carti- 
lage. 

The  side  of  the  epiglottis. 

The  side  of  the  epiglottis. 


To  compress  part  of  the 
pharynx. 

To  compress  the  pharynx, 
and  draw  the  os  hyoides  up- 
ward. 

To  move  the  pharynx  up- 
ward and  forward,  and  to 
compress  its  upper  part. 

BOUT  THE  GLOTTIS. 

To  open  the  glottis. 

To  open  the  glottis. 

To  draw  the  arytenoid  car- 
tilage forward. 

To  draw  them  toward  each 
other. 

To  shut  the  glottis. 

To  pull  the  epiglottis  ob- 
liquely downward. 

To  move  the  epiglottis  out- 
ward. 


72 


ANATOMICAL  CLASS  BOOK. 


MUSCLES  SITUATED  ON  THE  ANTERIOR  PART  OF  THE  ABDOMEN. 

.Arises  from, 

The  lower  edges  of  the 
eight  inferior  ribs  near  the 
cartilages. 

The  spinous  processes  of 
the  three  last  lumbar  verte- 
bra, back  of  the  sacrum,  and 
spine  of  the  ilium. 


the  ilium. 

Rectus  abdominis.  The  outside  of  the  sternum 

and  xyphoid  cartilage. 

Pyramidalis.  The  anterior  upper  part  of 

J the  pubis. 


Name. 

Obliquus  descendens  exter- 

nus. 

Obliquus  ascendens  inter- 

nus. 


ANATOMICAL  CLASS  BOOK. 


73 


MUSCLES  SITUATED  ON  THE  ANTERIOR  PART  OF  THE  ABDOMEN. 

Inserted  into  Use. 

The  linea  alba,  ossa  pubis,  To  compress  the  abdomen, 
and  spine  of  the  ilium. 

The  cartilages  of  all  the  To  compress  the  abdomen, 
false  ribs,  linea  alba,  and  pu- 
bis, and  sternum,  by  a flat 
tendon. 

Explanation  of  Fig.  34. 

g.  The  obliquus  internus,  with  its  tendon  divided,  to  show 

h.  The  pyramidalis. 

i.  The  rectus,  abdominis.  Beneath  the  internal  oblique  there  is 
situated 

k.  The  transversalis  abdominalis,  and 

l.  The  fascia  transversalis. 

The  tendons  of  the  abdominal  muscles,  form  junctions  in  front, 
where  their  broad  white  tendons  meet,  which  are  denominated 
lines  ; — and  that  which  runs  exactly  in  the  middle,  from  the  lower 
point  of  the  sternum,  to  the  pubis,  is  the  linea  alba  or  white  line. 
Again,  the  long  abdominal  muscles,  lying  each  side  of  this  linea 
alba,  are  intersected,  several  times,  between  their  two  extremities, 
by  similar  tendinous  lines,  which,  in  reality,  divides  them  into  a 
chain  of  muscles.  This  structure  has  reference  to  increasing  their 
power,  by  a series  of  contractions,  along  their  course,  which  thereby 
answers  a second  intention,  viz,  preserving  a symmetry  of  form.  By 
consulting'  Fig.  34,  page  72,  bolh  the  vertical  and  transverse  lines 
are  discoverable.  Statues  representing  action,  invariably'  exhibit 
the  muscles  of  the  bowels  thrown  into  ridges.  Upon  the  princi- 
ples adverted  to  in  the  preliminary  essay  on  myology,  without  these 
transverse  bands,  the  bellies  of  the  long  recti  muscle,  in  order  to 
pull  the  chest,  as  in  stooping  for  example,  while  seated  in  a chair, 
so  as  to  bring  the  breast  down  to  the  knees,  would  have  a bulk,  by 
the  process  of  contraction,  equal  to  a two  quart  measure.  B the 
introduction  of  the  transverse  tendinous  lines,  two  vastly  im;  (rant 
results  are  obtained,  — increased  power  and  beauty  of  form. 

The  linea  alba  throughout  To  compress  the  abdominal 
its  whole  length,  and  into  the  viscera, 
ensiform  cartilage. 


The  side  of  the  symphysis 
of  the  pubis. 

The  linea  alba,  below  the 
umbilicus. 


To  compress  the  abdomen, 
and  bend  the  trunk. 

To  assist  the  lower  portion 
of  the  rectus. 


7 


74 


ANATOMICAL  CLASS  BOOK,' 


MUSCLES  SITUATED  WITHIN  THE  PELVIS. 


Name. 

Obturator  internus. 
Coccygeus. 


Jh'ises  from 

The  foramen  ovale,  obtura- 
tor ligament,  ilium,  ischium, 
and  pubis. 

The  spinous  process  of  the 
ischium. 


MUSCLES  SITUATED  WITHIN  THE  CAVITY  OF  THE  ABDOMEN. 

Quadratus  lumborum.  The  posterior  part  of  the 

spine  of  the  ilium. 

Psoas  parvus.  The  transverse  process  of 

the  last  dorsal  vertebra. 


Fig.  35. 


Explanation  of  Fig  35 
K.  The  iliacus internus. 

R.  The  psoas  magnus. 

S.  The  obturator  exter- 
nus. 


S 


ANATOMICAL  CLASS  BOOK. 


75 


MUSCLES  SITUATED 

Inserted  into 

A large  pit  between  the  tro- 
chanters of  the  femur. 

The  extremity  of  the  sa- 
crum and  os  coccygis. 


WITHIN  THE  PELVIS. 

Use. 

To  roll  the  femur  obliquely 
outward. 

To  move  the  coccyx  for- 
ward and  inward. 


MUSCLES  SITUATED  WITHIN  THE  CAVITY  OF  THE  ABDOMEN. 

The  transverse  apophyses  To  support  the  spine  and 
of  the  loins  and  last  spurious  draw  it  to  one  side, 
rib. 

The  brim  of  the  pelvis,  To  bend  the  loins  forward, 
near  the  place  of  the  aceta- 
bulum. 

On  the  inside  of  the  broad  hip  bone,  os  innominatum,  seen  on  the 
opposite  page,  Fig.  35,  and  also  running  up  by  the  side  of  the  lumbar 
vertebrae,  thiee  muscles  have  their  oiigin,  — that  bear  a highly  im- 
portant part  in  the  locomotive  power  of  the  body.  In  these,  as  in 
every  other  place  in  the  system,  a two  fold  intention  is  answered. 
First,  — these  thiee  muscles  are  cushions,  — on  which  the  coils  of 
the  intestines  rest.  Without  them,  some  other  provision  would  have 
been  necessary,  as  a soft  bed  is  indispensable  for  then. , in  the  violent 
exercises  of  running,  leaping,  or  even  walking  Secondly,  the 
tendons  of  the  psoas  magnus  and  iliacus  internus,  are  sent  over  the 
brim  of  the  pelvis,  to  wind  down  the  inside  of  the  groin,  close  to  the 
bone,  to  reach  the  backside  of  the  thigh  bone,  where  they  are  fast- 
ened. Obscure  as  they  are,  these  muscles,  when  standing  on  our 
feet,  maintain  the  body  in  an  erect  position.  If  we  desire  to  move 
forward,  these  muscles  lift  up  the  whole  limb, — and  when  they  re- 
lax, the  foot  strikes  the  ground  again.  If,  while  sitting,  the  knee  is 
raised  towards  the  chest,  the  act  is  accomplished  by  these  two  mus- 
cles. In  walking  and  running,  therefore,  as  they  are  the  lifters-up 
of  the  leg,  their  services  could  not  be  dispensed  with.  A lumbar 
abscess,  a painful  disease,  wholly  forbidding  the  movement  of  the 
limb  of  the  side  in  which  it  occurs,  is  a collection  of  matter  under 
the  psoas  magnus,  and  next  to  the  back  bone,  near  the  line  R,  on 
the  plate.  As  the  abscess  cannot  be  very  safely  discharged  by  a 
surgical  operation,  through  the  muscles  ol  the  back,  in  protracted 
cases,  the  matter  sometimes  follows  the  muscles,  quite  into  the  limb, 
and  forces  its  way  down,  even  to  the  knee,  before  it  escapes.  This 
dreadfu^disease  has  been  induced,  by  lying  on  the  damp  ground, 
after  freely  exercising;  and  by  unnecessary  feats  of  strength,  in 
lifting  burdens,  in  the  careless  days  of  youthful  vigor. 


76 


ANATOMICAL  CLASS  BOOK. 


Name. 
Psoas  magnus. 


lliacus  interims. 


Arises  from 

The  bodies  and  processes 
of  the  last  dorsal  and  all  the 
lumbar  vertebrae. 

The  internal  surface  of  the 
spine  of  the  ilium. 


MUSCLES  SITUATED  ON  THE  ANTERIOR  PART  OF  THE  THORAX. 

Pectoralis  major.  The  clavicle,  sternum  and 

seven  true  ribs. 


Fig.  36. 


Stibclavius. 


The  cartilage  of  the  first  rib. 


The  third,  fourth,  and  fifth 
ribs. 


Pectoralis  minor. 


ANATOMICAL  CLASS  BOOK. 


77 


Inserted  into  Use. 

The  os  femoris,  a little  be-  To  bend  the  thigh  forward, 
low  the  trochanter  minor. 

The  femur  in  common  with  To  assist  the  psoas  magnus. 
the  psoas  magnus. 

MUSCLES  SITUATED  ON  THE  ANTERIOR  PART  OF  THE  THORAX. 

The  upper  and  inner  part  of  To  draw  the  arm  forward, 
the  humerus.  or  obliquely  forward. 

Explanation  of  Fig.  36. 

а.  The  pectoralis  major. 

б.  b.  The  obliquus  abdominis  externus  descendens : beneath  these 
muscles  the  following: — 

c.  The  pectoralis  minor. 

d.  The  serratus  magnus  antieus. 

e.  The  external  intercostal  muscles. 

f.  The  internal  intercostal  muscles. 

g.  The  obliquus  abdominis  internus  ascendens. 

By  returning  to  the  anatomy  of  the  ribs,  it  is  there  shown  that 
they  are  constructed  to  move  : — breathing  is  effected  by  increasing 
and  diminishing  the  capacity  of  the  chest,  as  the  lungs  are  inflated 
or  collapsed.  To  carry  on  this  operation,  an  appropriate  class  of 
muscles  take  their  rise  on,  and  about  the  libs  and  sternum,  to  be  ex- 
clusively engaged  in  this  respitory  action.  Between  the  edges  of 
the  ribs,  short  oblique  muscles,  one  the  internal  and  the  other  the 
external , crossing  each  other,  like  suspenders  on  a man’s  back,  — 
are  untiring  in  their  labors : — when  they  contract,  the  ribs  are 
brought  together;  and  when  relaxed,  the  diameter  of  the  chest  is 
enlarged.  All  the  muscles  on  the  breast  and  sides,  are  remotely 
respitory  agents.  If  the  arms  are  fixed,  by  their  contraction  the 
ribs  are  drawn  outwardly.  Asthmatic  persons,  because  the  small 
intercostal  muscles  do  not  relax  enough,  bring  the  pectoral  muscles 
to  their  aid,  by  raising  their  hands  and  holding  on  to  a door,  or  a 
beam,  for  example,  above  the  head.  This  enables  them  to  pull 
open,  as  it  were,  the  bottom  of  the  chest.  Ladies  often  swoon  and 
sometimes  drop  down  dead  instantly,  in  consequence  of  lacing  the 
chest  so  tightly,  that  the  ribs  cannot  possibly  move. 


The  under  surface  of  the 
clavicle. 

The  coracoid  process  of  the 
scapula. 

7* 


To  move  the  clavicle  down- 
ward. 

To  roll  the  scapula. 


78 


ANATOMICAL  CLASS  BOOK. 


Name. 

Serratus  major  anticus. 


Arises  from 

The  eight  superior  ribs. 


MUSCLES  SITUATED  BETWEEN  THE  RIBS  AND  WITHIN  THE 
THORAX. 


Intercostales  externi. 
Intercostales  interni. 

Triangularis,  or 

Sterno-costalis. 

. 1 


The  lower  edge  of  each 
upper  rib. 

Like  the  former,  their  fibres 
are  directed  from  behind  for- 
ward. 

The  middle  and  inferior 
part  of  the  sternum. 


MUSCLES  SITUATED  ON  THE  ANTERIOR  PART  OF  THE  NECK, 
CLOSE  TO  THE  VERTEBRAL 


Longus  colli. 


Rectus  internus  capitis  ma- 
jor. 

Rectus  internus  capitis  mi- 
nor. 

Rectus  capitis  lateralis. 


The  bodies  of  the  three 
upper  dorsal  and  transverse 
processes  of  the  four  last 
cervical. 

The  transverse  processes  of 
the  five  last  cervical  vertebra. 

The  fore  part  of  the  atlas. 

The  transverse  process  of 
the  atlas. 


MUSCLES  SITUATED  ON  THE  POSTERIOR  PART  OF  THE  TRUNK. 


Trapezius,  or  Cucullaris. 


Latissimus  dorsi. 


Serratus  posticus  inferior- 


The  os  occipitis  and  the 
spinous  processes  of  all  the 
vertebrae  of  the  neck  and 
back. 

The  spine  of  the  ilium  spin- 
spinous  process  of  the  sacrum, 
lumbar  and  inferior  dorsal  ver- 
tebras ; adheres  to  the  scapula 
and  inferior  false  ribs. 

The  spinous  processes  of 
the  two  last  dorsal  and  three 
lumbar  vertebra. 


ANATOMICAL  CLASS  BOOK. 


79 


Inserted  into  Use. 

The  base  of  the  scapula.  To  bring  the  scapula  for- 

ward. 


MUSCLES  SITUATED  BETWEEN  THE  RIBS  AND  WITHIN  THE 
THORAX. 

The  superior  edge  of  each  To  elevate  the  ribs, 
lower  rib. 


The  cartilages  of  the  five  To  depress  the  cartilages 
last  true  ribs.  of  the  ribs. 


MUSCLES  SITUATED  ON  THE  ANTERIOR  PART  OF  THE  NECK, 
CLOSE  TO  THE  VERTEBRA. 

The  anterior  tubercle  of  the  To  pull  the  neck  to  one 
dentatus.  side. 


The  cuneiform  process  of 
the  os  occipitis. 

The  os  occipitis,  near  the 
condyloid  process. 

The  os  occipitis,  near  the 
mastoid  process. 


To  bend  the  head  forward. 

To  assist  the  former. 

To  move  the  head  to  one 
side. 


MUSCLES  SITUATED  ON  THE  POSTERIOR  PART  OF  THE  TRUNK. 


The  clavicle,  part  of  the 
acromion,  and  the  spine  of  the 
scapula. 

The  os  humeri,  between  its 
two  tuberosities  in  the  edge 
of  the  groove  for  the  tendon 
of  the  biceps  muscle. 

The  lower  edge  of  the  three 
or  four  lowermost  ribs,  near 
their  cartilages. 


To  move  the  scapula,  bend 
the  neck,  and  pull  the  head 
backward. 

To  draw  the  os  humeri 
backward,  and  to  roll  it  upon 
its  axis. 


To  draw  the  ribs  outward, 
downward,  and  backward. 


80 


ANATOMICAL  CLASS  BOOK. 


Name. 

Rhomboideus. 

Splenius. 

Serratus  superior  posticus. 

Spinalis  dorsi. 

Levatores  costarum,  or 
Supra-cotales. 

Sacro-lumbalis. 


Arises  from 

The  spinous  processes  of 
the  three  last  cervical,  and 
four  first  dorsal  vertebrae. 

The  spines  of  the  four  last 
cervical,  and  four  superior  dor- 
sal vertebrae. 

The  spinous  processes  of 
the  three  last  cervical,  and  two 
superior  dorsal  vertebrae. 

Two  spinous  processes  of 
the  loins,  and  three  lower  of 
the  back. 

The  transverse  processes  of 
the  last  cervical  and  the  dor- 
sal vertebrae. 

The  sacrum,  spine  of  the 
ilium,  and  the  spinous  and 
transverse  processes  of  the 
lumbar  vertebrae. 


Fig.  37. 


Explanations  of 
Fig.  37. 

a.  The  trapezi- 
us. 

b.  The  latissimus 

dorsi. 

c.  The  rhomboi- 
deus minor. 

d.  The  rhomboi- 
deus major. 

e.  The  serratus 
posticus  inferior. 

f.  The  levator 
anguli  scapulae. 

Blocks  were  in- 
troduced to  repre- 
sent the  figure  in  a 
horizontal  position, 
that  the  muscles 
might  be  more  dis- 
tinctly seen. 


ANATOMICAL  CLASS  BOOK. 


81 


Inserted  into 

The  basis  of  the  scapula,  at 
its  upper  and  lower  part. 

The  two  first  cervical  verte- 
bra, and  the  side  of  the  os 
occipitis. 

The  second,  third,  and  fourth 
ribs,  by  three  neat  fleshy 
tongues. 

All  the  spinous  processes  of 
the  back,  except  the  first. 

The  angles  of  the  ribs. 

The  lower  edge  of  each  rib, 
by  a flat  tendon. 


Use. 

To  move  the  scapula  up- 
wards and  backward. 

To  move  the  head  back- 
ward, and  also  to  one  side. 

To  expand  the  thorax,  by 
elevating  the  ribs. 

To  extend  the  vertebra. 


To  lift  the  ribs  upward. 

To  draw  the  ribs  down- 
ward, to  move  the  body  upon 
its  axis,  to  assist  the  longissi- 
mus  dorsi,  and  to  turn  the  neck 
back,  or  to  one  side. 


All  the  muscles  of  the  back,  clearly  defined  in  Fig.  37,  on  the 
opposite  page,  are  broad,  thin,  and  generally  produce  the  slow  mo- 
tion of  the  limbs.  In  the  middle  of  the  trapezius , marked  a,  is  a 
white  line,  where  the  fibres  of  the  muscle,  on  either  side  meet  and 
adhere  to  the  spinous  processes  of  the  bones  of  the  neck.  On  this 
line,  in  quadrupeds,  is  placed  a powerfully  strong  cord,  by  the  far- 
riers called  paxwax,  — but  by  anatomists  — ligamentum  nucha:, 
which,  being  attached  to  the  back  bone,  between  the  shoulders,  pre- 
vents their  heavy  head  from  drooping  to  the  ground,  It  will  not  re- 
lax : — when  they  drink  or  feed,  on  a level  with  their  feet,  the  nose, 
even  by  a voluntary  effort,  barely  reaches  to  the  earth. 


92 


ANATOMICAL  CLASS  BOOK. 


Fiff.  38. 


ANATOMICAL  CLASS  BOOK. 


83 


Explanation  of  Fig.  38. 

a,  upper  portion  of  the  trapezius  ; i.  sterno  cleido  mastoideus  ; d. 
the  deltoid  portion  of  the  trapezius ; f.  the  latissimus  dor  si ; 
n.  n.  n.  n.  portions  of  the  latissimus,  rising  by  (limitations  from  the 
ribs  ; g.  and  b.  tendinous  continuation  of  the  latissimus  into  the 
fibres  of  the  gluteus  maxirnus  ; h.  the  deltoides  muscle,  to  raise  the 
arm;  k,  e,  m,  the  infra  spinatus,  belonging  to  the  shoulder;  c,  the 
clavicular  portion  of  the  deltoides  ; l,  the  intermingling  of  the  fibres 
of  the  gluteus  maximus,  and  latissimus  dorsi. 


The  artist  was  particularly  fortunate  in  delineating  the  muscles  in 
the  accompanying  diagram.  No  plate  could  more  accurately  show 
the  relation  which  one  bears  to  the  other,  nor  more  truly  represent 
the  converging  fibres,  all  centering  in  the  tendons.  As  in  the  de- 
monstration of  the  eye,  it  can  also  be  said  here,  — that  there  are 
coats  of  muscles  on  the  back  and  sides.  One  overlaps  the  edges  of 
another,  in  such  a perfect  manner,  as  to  leave  no  deep  spaces  : — an 
even  covering  is  thus  spread  over  the  skeleton.  The  latissimus 
dorsi.  marked/,  is  one  of  the  most  beautiful  in  the  body;  and  its 
utility  is  proved  every  moment.  Its  office  is  to  bring  down  the  hand. 
Before  man  invented  instruments  which  have  superseded,  to  consid- 
erable extent,  the  primitive  use  of  the  hand,  in  some  particulars,  — 
his  fist  was  a mallet, — the  arm  the  handle,  and  this  muscle,  the 
power  that  gave  force  to  the  blow.  Those  mechanics  who  are  con- 
stantly using  hammers,  and  axes,  increase  its  size  and  strength, 
amazingly.  If  the  arm,  on  the  other  hand,  be  firmly  fixed,  in  a 
horizontal  position,  the  digitations  marked  n,  n,  n,  n,  by  their  strong 
hold  upon  the  false  ribs,  would  open  the  bottom  of  the  chest,  quite 
effectually.  Over  the  shoulder  joint,  and  from  thence,  running  to 
the  middle  of  the  arm  bone,  is  a splendid  muscle,  — the  deltoides , 
marked  h,  which  raises  the  arm  to  a level  with  the  shoulder;  its 
lateral  portions,  even  carry  the  elbow  very  much  above  the  level 
of  their  origin.  If  it  were  divided,  no  remaining  muscle  could  per- 
form its  office.  Just  above  f,  winding  partially  under  the  deltoides, 
is  that  muscle  which  extends  the  arm.  The  name  of  triceps  exten- 
sor cubiti  is  given  it,  because  it  arises  by  three  heads,  which  uniting 
in  one  tendon,  passes  the  elbow  joint,  on  the  back  of  the  arm,  to  be 
inserted  into  the  ulna,  or,  as  the  bone  is  sometimes  called,  the  cubit. 
Lastly,  k,  e , m,  directs  the  eye  to  the  infra  spinatus,  arising  on  the 
external  surface  of  the  shoulder  blade,  and  inserted  into  the  arm 
bone.  By  its  contraction,  the  arm  is  raised  a very  little,  and  carried 
backward;  — its  tendon,  as  it  passes  over  the  shoulder  joint,  adheres 
to  the  capsular  ligament  and  keeps  it  drawn  out,  so  that  it  may  not 
be  pinched,  by  the  rolling  motion  of  the  ball  in  the  socket. 


84 


ANATOMICAL  CLASS  BOOK. 


Name. 

Longissimus  dorsi. 
Complexus. 

Trachelo-mastoideus. 
Levator  scapulae. 
Semi-spinalis  dorsi. 
Multifidus  spinae. 

Semi-spinalis  colli,  or 
Spinalis  cervicis. 

Transversalis  colli. 

Rectus  capitis  posticus  ma- 
jor. 

Rectus  capitis  posticus  mi- 
nor 

Obliquus  capitis  superior. 
Obliquus  capitis  inferior. 
Scalenus. 

Interspinales. 

Inter-transversales. 


Arises  from 

The  same  parts  as  the  for- 
mer, and  by  one  common 
broad  tendon. 

The  transverse  processes  of 
the  four  inferior  cervical,  and 
seven  superior  dorsal  verte- 
brae. 

The  transverse  processes  of 
the  five  lower  cervical  and 
three  upper  dorsal  vertebrae. 

The  transverse  processes  of 
the  four  superior  cervical  ver- 
tebrae. 

The  transverse  processes  of 
the  7th,  8th,  -9th,  and  10th 
dorsal  vertebrae. 

The  sacrum,  ilium,  oblique 
and  transverse  processes  of 
the  lumbar,  the  transverse  of 
the  dorsal,  and  four  cervical 
vertebrae. 

The  transverse  processes 
of  the  six  upper  dorsal  verte- 
brae. 

The  transverse  processes  of 
the  five  upper  dorsal  verte- 
brae. 

The  transverse  process  of 
the  second  cervical  vertebrae. 

The  first  vertebrae  of  the 
neck. 

The  transverse  process  of 
the  atlas. 

The  spinous  process  of  the 
dentatus. 

The  upper  surface  of  the 
first  and  second  rib. 

Between  the  spinous  pro- 
cesses of  the  six  inferior  cer- 
vical vertebrae. 

Between  the  transverse 
processes  of  the  vertebrae. 


ANATOMICAL  CLASS  BOOK. 


So 


Inserted  into 

The  transverse  processes  of 
all  the  dorsal  and  one  cervical 
vertebra. 

The  middle  of  the  os  occi- 
pitis,  at  its  tubercle. 


The  os  occipitis,  behind  the 
mastoid  process  of  the  tempo- 
ral bone. 

The  upper  angle  of  the 
scapula. 

The  spinous  processes  of 
the  four  superior  dorsal  and 
the  last  cervical  vertebra. 

The  spinous  processes  of  the 
lumbar  dorsal,  and  cervical 
vertebra,  except  the  atlas. 


The  spinous  processes  of 
the  five  middle  cervical. 

The  transverse  processes  of 
the  cervical  vertebra. 

The  lower  ridge  of  the  os 
occipitis. 

The  os  occipitis  at  its  tu- 
bercle. 

The  end  of  the  lower  occi- 
pital ridge. 

The  transverse  process  of 
the  atlas. 

The  transverse  processes  of 
the  cervical  vertebrae. 

The  spinous  processes  of 
the  vertebras  above. 

The  transverse  processes  of 
the  vertebrae  above. 


Use. 

To  stretch  the  vertebra  ot 
the  back,  and  keep  the  trunk 
erect. 

To  draw  the  head  back- 
ward. 


To  draw  the  head  backward. 


To  move  the  scapula  for- 
ward and  upward. 

To  extend  the  ^pine  ob- 
liquely backward. 

To  extend  the  back,  and 
draw  it  backward,  or  to  one 
side,  and  prevent  the  spine 
from  being  too  much  bent  for- 
ward. 

To  stretch  the  neck  ob- 
liquely backward. 

To  turn  the  neck  obliquely 
backward,  and  to  one  side. 

To  extend  the  head,  and 
draw  it  backward. 

To  assist  the  rectus  major. 

To  draw  the  head  back- 
ward. 

To  draw  the  face  to  one 
side. 

To  move  the  neck  forward, 
or  to  one  side. 

To  draw  the  spinous  pro- 
cesses towards  each  other. 

To  draw  the  transverse  pro- 
cesses towards  each  other. 


8 


S6 


ANATOMICAL  CLASS  BOOK. 


MUSCLES  OF  THE  SUPERIOR  EXTREMITIES, 


Name. 

Supra-spinatus. 

Infra  spinatus. 


Arises  from 

The  basis,  spine,  and  upper 
end  of  the  scapula. 

The  cavity  below  the  spine 
of  the  scapula. 


Fig.  39 


Explanation  of  Fig.  39. 

a.  The  supra-spinatus. 

b.  The  infra  spinatus. 

c.  The  teres  minor. 

d.  The  teres  major. 

e.  The  latissimus  dorsi. 

f.  The  deltoid. 

g.  The  triceps  extensor  cubiti. 


Teres  minor. 
Teres  major. 
Deltoides. 

Coraco  brachialis. 


The  inferior  edge  of  the 
scapula. 

T he  inferior  angle  and  edge 
of  the  scapula. 

The  cavicle,  and  the  acro- 
mion and  spine  of  the  scapula. 

The  coracoid  process  of  the 
scapula. 


ANATOMICAL  CLASS  BOOK. 


87 


MUSCLES  OF  THE  SUPERIOR  EXTREMITIES. 


Inserted  into  Use. 

A large  tuberosity  at  the  To  raise  the  arm. 
head  of  the  os  humeri. 

The  upper  part  of  the  same  To  roll  the  os  humeri  out- 
tuberosity.  ward. 

Anatomists  have  sought  for  an  explanation  of  the  superiority  of 
the  right  hand,  over  the  left,  in  the  muscles,  arteries  and  nerves  of 
the  arm  ; but  no  very  satisfactory  light  has  been  thrown  upon  the 
subject.  At  one  time,  it  was  a common  mode  of  getting  over  the 
difficulty,  to  say  that  the  preference  we  give  to  the  right  hand  arises 
from  its  superior  strength;  and  that  quality  is  owing  to  the  man- 
ner in  which  the  artery  arises  from  the  arch  of  the  aorta,  just  above 
the  heart.  There  is  certainly  a considerable  difference  in  the  size 
of  the  arteries  in  the  two  aims.  The  right  in  this  respect,  being 
the  largest,  derives  its  blood  more  directly  from  the  fountain  head. 
As  the  power  of  the  muscle  actually  depends  on  the  blood  circulat- 
ed in  its  substance,  it  was  very  natural  to  refer  the  origin  of  its  su- 
perior force  to  this  cause.  Here  the  inquiry  has  rested,  so  far  as 
anatomical  demonstration  is  concerned.  But  a formidable  objection 
to  that  old  fashioned  theory  arises,  when  we  find  a left-handed  man, 
whose  arm  does  not  differ  essentially  from  any  other  person’s  left  arm, 
and  ambidexters,  men  using  one  hand  just  as  well  as  the  other,  for 
example,  in  writing,  throwing  balls,  turning  a gim'blet,  using  a cabi- 
net-maker’s plane,  Arc,  seem  to  be  entirely  out  of  the  reach  of  the 
old  stereotyped  theory  about  the  artery.  The  preference,  given  to 
the  right  hand,  conduces  to  its  muscular  development ; it  is  both 
larger,  and  stronger,  by  use.  So  it  is  with  the  right  foot,  and  lvmce 
the  extreme  difficulty,  with  some,  of  wearing  a pair  of  shoes  made 
on  one  last. 

The  evidence  is  pretty  conclusive,  from  the  universality  of  the 
law,  which  embraces  all  the  inferior  animals,  as  well  as  man,  that  it 
was  expressly  designed  by  the  Creator,  that  the  limbs  on  one  side  of 
the  body  should  possess  certain  physical  advantages  over  the  other. 
Both  rapidity  of  motion,  and  strength,  are  thus  combined,  constantly 
improved  upon  by  practice,  and  a certain  mechanical  excellence 
is  thus  bestowed,  without  which  we  should  be  incompetent  to 
the  discharge  of  those  duties  which  devolve  upon  us. 


The  greater  tuberosity  of 
the  humerus. 

The  side  of  the  groove  for 
the  long  tendon  of  the  biceps. 

The  anterior  and  middle 
part  of  the  os  humeri. 

The  middle  and  inner  side 
of  the  os  humeri. 


To  assist  the  former. 

To  assist  in  rotating  the 
arm. 

To  raise  the  arm. 

To  roll  the  arm  forward  and 
upward. 


66 


ANATOMICAL  CLASS  BOOK. 


MUSCLES  SITUA 

Name. 
Subscapularis. 

Biceps  flexor  cubiti. 

Bvachialis  internus. 

Triceps  extensor  cubiti. 

Anconeus. 

MUSCLES  SITUATED 

Supinator  radii  longus. 

Extensor  carpi  radialis  lon- 
gior. 

Extensor  carpi  radialis  bre- 
vior. 

Extensor  digitorum  commu- 
nis. f 

Extensor  minimi  digiti. 

Extensor  carpi  ulnaris. 

Flexor  carpi  ulnaris. 

Palmaris  longus.  , 

Flexor  carpi  radialis, 
Pronator  radii  teres. 

Sppinator  radii  brevis. 


ON  THE  OS  HUMERI. 

Arises  from 

The  basis,  superior  and  in- 
ferior edge  of  the  scapula. 

Two  heads,  one  from  the 
coracoid  process,  the  other, 
called  the  long  head,  from  the 
edge  of  the  glenoid  cavity 
of  the  scapula. 

The  os  humeri  at  each  side 
of  the  tendon  of  the  deltoides. 

The  neck  of  the  scapula, 
and  the  neck  and  middle  of 
the  humerus. 

The  external  condyle  of 
the  humerus. 

ON  THE  FORE  ARM. 

The  external  condyle  of  the 
humerus. 

The  external  condyle  of  the 
humerus. 

The  external  condyle  of  the 
humerus. 

The  external  condyle  of  the 
os  humeri. 

The  outer  condyle  of  -the 
humerus. 

The  outer  condyle  of  the  os 
humeri. 

The  inner  Condyle  of  the 
humerus  and  olecranon. 

The  internal  condyle  of  the 
os  humeri. 

The  internal  condyle  of  the 
os  humeri. 

The  internal  condyle  of  the 
humerus  and  coronoid  process 
of  the  ulna. 

The  outer  condyle  of  the 
humerus  and  edge  of  the  ulna. 


ANATOMICAL  CLASS  BOOK. 


89 


MUSCLES  SITUATED  ON  THE  OS  HUMERI. 


Inserted  into 

The  protuberance  at  the 
head  of  the  os  humeri. 

The  tuberosity  at  the  upper 
end  of  the  radius,  at  its  fore 
part,  and  a little  below  its 
neck. 

The  coronoid  process  of  the 
ulna. 

The  upper  and  outer  part 
of  the  olecranon. 

The  back  part  or  ridge  of 
the  ulna. 


Use. 

To  roll  the  arm  inward. 

To  bend  the  fore  arm, 
which  it  does  with  great 
strength,  and  to  assist  the 
supinators. 

To  assist  in  bending  the 
fore  arm. 

To  extend  the  fore  arm. 


To  assist  in  extending  the 
fore  arm. 


MUSCLES  SITUATED  ON  THE  FORE  ARM. 


The  radius  near  the  styloid 
process. 

The  metacarpal  bone  of  the 
fore  finger. 

The  metacarpal  bone  of  the 
middle  finger. 

The  back  of  all  the  bones 
of  the  fingers. 

The  second  joint  of  the 
little  finger. 

The  metacarpal  bone  of  the 
little  finger. 

The  os  pisiforme,  at  its  fore- 
part. 

The  annular  ligament  of  the 
wrist,  and  there  forms  the 
aponeurosis  of  the  hand. 

The  metacarpal  bone  of  the 
fore  finger. 

The  outer  ridge  of  the  radi- 
us, about  the  middle  of  its 
length. 

The  anterior,  inner,  and 
upper  part  of  the  radius. 


To  assist  in  turning  up  the 
palm  of  the  hand. 

To  extend  the  wrist. 

To  assist  the  former. 

To  extend  the  fingers. 

To  assist  in  extending  the 
fingers. 

To  assist  in  extending  the 
wrist. 

To  assist  in  bending  the 
hand. 

To  bend  the  hand. 


To  bend  the  hand. 

To  roll  the  hand  inward. 


To  roll  the  radius  outward, 
and  assist  the  anconeus. 


S* 


90 


ANATOMICAL  CLASS  BOOK. 


Name.  Arises  from 

Extensor  ossis  metacarpi  The  middle  of  the  ulna,  in- 
pollicis  manus.  terosseous  ligament  and  radius. 


Fig.  40. 


Fig.  41. 


ANATOMICAL  CLASS  BOOK 


91 


Inserted,  into  Use. 

The  os  trapezium,  and  first  To  stretch  the  first  bone  of 
bone  of  the  thumb.  the  thumb  outward. 


Explanation  of  Fig.  40. 

f.  extensor  digitorum  communis,  for  extending  the  fingers ; h,  ex- 
tensor proprius  minimi  digid,  to  extend  the  little  finger  ; f where 
it  unites  with  others ; i,  extensor  carpi  ulnaris ; l,  anconeus , ex- 
tensorossis  metecarpi  pollicis  ; e,  extensor  primi  internodii pollicis  ; 
e,  extensor  secundi  internodii  pollicis;  d,  indicator ; g,  annular 
ligament  of  the  wrist ; m,  will  be  recognised  ; k,  an  abductor  of 
the  little  finger  ; e,  supinator  radii  longus. 


Explanation  of  Fig.  41. 

a.  pronator  teres ; b,  flexor  carpi  radialis  ; c,  d,  palmaris  longus  , 
e,  flexor  carpi  ulnaris  ; g,  flexor  carpi  radialis  Ion goir. 

Between  the  elbow  and  ends  of  the  fingers  there  are  about  fifty 
muscles.  Some  of  them, — particularly  those  by  the  sides  of  the  fing- 
ers, are  quite  short  and  delicate.  All  the  quick  short  motions  of  the 
fingers  are  made  by  them.  Their  name,  musculi  fidicinales, 
fiddling  muscles,  in  old  books,  is  quite  appropriately  given,  because 
the  strings  of  the  instrument  are  operated  upon  almost  entirely  by 
them.  A back  and  front  view  of  the  fore  arm  is  presented  in 
the  opposite  page.  Fig’s  40,  and  41,  in  which  all  the  long  mus- 
cles, on  the  inside  flexors,  and  on  the  back  of  the  arm  exten- 
sors, may  be  very  accurately  observed.  Just  under  the  skin,  a 
silvery,  tough  membrane,  like  a silk  case,  is  drawn  closely  over  the 
muscles,  to  keep  them  from  swelling  too  much,  in  their  contractions. 
As  before  remarked,  the  strength  which  a muscle  exerts,  by  being 
pressed  down  to  the  bone,  when  in  action,  is  increased  a hundred 
fold.  The  beauty  and  proportion  of  the  limb  is  wholly  preserved 
by  the  case,  which  is  called  fascia.  It  is  taken  away,  in  these 
plans,  in  order  to  show  more  distinctly  the  parts  below. 


92 


ANATOMICAL  CLASS  BOOK. 


Name. 


Arises  from 


Extensor  primi  internodii.  Near  the  middle  of  the  ulna> 

interosseous  ligament,  and 
radius. 

Extensor  secundi  interno-  The  back  of  the  ulna  and 


dii. 

Indicator. 


interosseous  ligament. 
The  middle  of  the  ulna. 


Fig.  42. 


Fig.  43. 


ANATOMICAL  CLASS  BOOK. 


93 


Inserted  into 

The  convex  part  of  the 
second  bone  of  the  thumb. 

The  third  and  last  bone  of 
the  thumb. 

The  metacarpal  bone  of  the 
fore  finger. 


Use. 

To  extend  the  second  bone 
of  the  thumb  outward. 

To  stretch  the  thumb  ob- 
liquely backward. 

To  extend  the  fore  finger. 


Explanation  of  Fig.  42. 

d,  e,  flexor  digit orurn  sublimis,  attached  to  the  second  bone  of 
each  finger,  by  four  tendons,  to  bend  the  second  joint, — f h.  flexor 
longus  policis  manus,  to  bend  the  thumb  ; a , b,  c,  pronator  teres , 
to  pronate  the  hand  ; g,  a slit  in  the  tendons  of  the  flexor  digitorum 
for  the  passage  of  four  other  tendons  of  another  muscle  which  go 
to  the  points  of  the  fingers,  for  bending  the  last  joint. 


Explanation  of  Fig.  43. 

c,  d,  d,  the  pronator  quadratus,  is  one  of  two  small  muscles 
for  pronating  the  hand;  a,  b,  the  other, — pronator  teres. 


In  Fig’s.  42,  and  43,  the  muscles  are  distinctly  engraven,  which 
roll  the  fore  arm  in  supination  and  pronation.  By  turning  a key 
in  a door-lock,  both  sets  are  called  into  action,  and  it  is  recommend- 
ed to  the  reader  to  do  it,  and  at  the  same  time  to  feel  the  contractions 
of  the  muscles  with  the  other  hand.  Fig.  43,  the  bones  are  made 
so  plain,  as  to  show  the  exact  relation  which  the  pronators  have  to 
them.  On  the  other,  Fig.  e,  points  to  the  four  tendons  of  the 
muscle  that  bends  the  last  bone  of  the  fingers.  Looking  back  to  Fig. 
41,  page  90,  it  is  there  concealed  by  the  flexor  of  the  second  bone  of 
the  fingers.  This,  in  order  to  reach  its  place  of  destination,  pierces, 
as  it  were,  the  tendons  of  the  upper  muscle,  and  thus  sends  its  own 
tendons  onward,  through  the  slit. 


94 


ANATOMICAL  CLASS  BOOK. 


Name. 

Flexor  digitorurn  sublimis. 


Flexor  digitorurn  profundus 
vel  perforans. 

Flexor  longus  pollicis. 

Pronator  radii  quadratus 


Arises  from 

The  inner  condyle  of  the  os 
humeri,  coronoid  process  of  the 
ulna,  and  upper  part  of  the 
radius. 

The  upper  part  of  the  ulna, 
and  interosseous  ligament. 

The  upper  and  fore  part  of 
the  radius. 

The  inner  and  lower  part 
of  the  ulna. 


MUSCLES  SITUATED  CHIEFLY  ON  THE  HAND. 


Lurnbricales. 

Flexor  brevis  pollicis  manus. 

Opponens  pollicis. 

Abductor  pollicis  manus. 

Abductor  pollicis  manus. 

Abductor  indicis  manus. 

Palmaris  brevis. 

Abductor  minimi  digiti  man- 
us. 

Abductor  minimi  digiti. 
Flexor  parvus  minimi  digiti. 
Interossei  interni,  and 
Interossei  externi. 


The  tendons  of  the  flexor 
profundus. 

The  os  trapezoides,  liga- 
ment of  the  wrist,  and  the  os 
magnum. 

The  os  scaphoides  and  liga- 
ment of  the  wrist. 

The  annular  ligament,  and 
os  trapezium. 

The  metacarpal  bone  of  the 
middle  finger. 

The  first  bone  of  the  thumb, 
and  os  trapezium. 

The  annular  ligament,  and 
palmar  aponeurosis. 

The  annular  ligament  and 
os  pisiforme. 

The  os  cuneiforme  and  car- 
pal ligament. 

The  annular  ligament  and 
os  cuneiforme. 

The  metacarpal  bones. 


MUSCLES  OF  THE  INFERIOR  EXTREMITIES. 

The  anterior  edge  of  the 
os  pubis. 


Pectinalis. 


ANATOMICAL  CLASS  BOOK. 


95 


Inserted  into 

The  second  bone  of  each 
finger,  after  being  perforated 
by  the  tendons  of  the  profun- 
dus. 

The  fore  part  of  the  last 
bone  of  each  of  the  fingers. 

The  last  joint  of  the  thumb. 

The  radius  opposite  to  its 
origin. 


Use. 

To  bend  the  second  joint  of 
the  fingers  upon  the  first,  and 
the  first  upon  the  metacarpal 
bones. 

To  bend  the  last  joint  of  the 
fingers. 

To  bend  the  last  joint  of  the 
thumb. 

To  roll  the  radius  inward. 


MUSCLES  SITUATED  CHIEFLY  ON  THE  HAND. 


The  tendons  of  the  extensor 
digitovum  communis. 

The  ossa  sesamoidea  and 
second  bone  of  the  thumb. 

The  first  bone  of  the  thumb. 

The  root  of  the  first  bone  of 
the  thumb. 

The  root  of  the  first  bone  of 
the  thumb. 

The  first  bone  of  the  fore 
finger  posteriorly. 

The  metacarpal  bone  and 
skin  of  the  little  finger. 

The  first  bone  of  the  little 
finger. 

The  metacarpal  bone  of  the 
little  finger. 

The  first  bone  of  the  little 
finger. 

The  sides  of  the  metacarpal 
bones. 


To  bend  the  first  and  extend 
the  second  phalanx. 

To  bend  the  second  joint  of 
the  thumb. 

To  bend  the  thumb. 

To  draw  the  thumb  from 
the  fingers. 

To  pull  the  thumb  toward 
the  fingers. 

To  move  the  fore  finger  to- 
wards the  thumb. 

To  contract  the  palm  of  the 
hand. 

To  draw  the  little  finger 
from  the  rest. 

To  move  that  bone  toward 
the  rest. 

To  draw  the  little  finger 
from  the  rest. 

To  extend  the  fingers, 
and  move  them  toward  the 
thumb. 


MUSCLES  OF  THE  INFERIOR  EXTREMITIES. 

The  upper  part  of  the  linea  To  bend  the  thigh, 
aspera  of  the  femur. 


Triceps  adductor  feinoris. 


9 G 


ANATOMICAL  CLASS  BOOK. 


Name. 

Adductor  longus  femo- 
ris. 

Adductor  brevis  femo- 
ris. 

Adductor  magnus  femo- 
ris. 


Arises  from 

The  upper  and  fore  part  of 
the  pubis. 

The  fore  part  and  ramus  of 
the  os  pubis. 

The  lower  and  fore  part  of 
the  ramus  of  the  pubis. 


Fig.  44. 


Explanation  of  Fig.  . 

c.  The  gluteus  medius. 

d.  The  pyriformis. 

e.  The  geminus  superior. 
f The  geminus  interior. 

g.  The  obturator  internus. 
g*.  The  quadrator  femoris. 

h.  The  biceps  flexor  cruris. 

i.  The  semitendinosus. 

k.  The  semimembranosus 

l.  The  superficial  gluteal 
artery  and  nerve. 

m.  The  greatischiaticnerve. 

n.  The  ischiatic  artery. 

o.  The  popliteal  nerve. 

p.  The  fibular  or  peroneal 
P nerve. 

q.  The  popliteal  vein. 

r.  The  popliteal  artery. 

s.  The  internal  pudic  artery 
vein,  and  nerve. 

t.  t.  The  muscles  on  the 
anterior  part  of  the  thigh. 


ANATOMICAL  CLASS  BOOK. 


97 


Inserted  into 

The  middle  and  back  part 
of  the  linea  aspera. 

The  inner  and  upper  part 
of  linea  aspera. 

The  whole  length  of  the 
linea  aspera. 


Use. 

To  bend  the  thigh. 

To  bend  the  thigh,  and 
move  it  inward. 

To  move  the  thigh  inward, 
and  assist  in  bending  it. 


Besides  the  muscles,  nerves,  veins,  tendons,  bands,  and  ligaments, 
there  are  absoi  bents — an  exceedingly  minute  class  of  tubes,  of  the 
utmost  importance  in  the  animal  economy.  From  the  inner  edge 
of  the  great  toe,  to  the  groin,  there  is  a chain  of  absorbents,  re- 
sembling, when  magnified  by  a lens,  a multitude  of  threaded  eggs. 
It  is  the  office  of  the  absorbents  to  pick  up  whatever  might  otherwise 
have  been  wasted,  and  return  it  to  the  heart,  that  it  may  be  appro- 
priated to  the  wants  of  the  body.  These  egg-shaped  particles  are 
receiving  organs,  immensely  larger  than  the  tubes  which  bring  into 
them  the  fluids  they  suck  up  about  the  muscles.  By  the  agency  of 
these  small  bodies,  which  are  greedy  to  seize  whatever  is  presented 
to  them,  the  physician  is  able  to  convey  medicines  into  the  circula- 
tion, when  they  could  not  be  taken  into  the  stomach.  It  ma3'  be 
desirable  to  salivate,  or  in  other  words,  to  increase  the  quantity  of 
fluid  in  the  mouth,  in  order  to  overcome  some  local  disease,  but  as 
mercury,  in  the  form  best  adapted  to  produce  that  effect,  would  be 
injurious  to  swallow,  it  is  rubbed  on  the  skin,  over  these  lymphat- 
ics or  absorbents,  being  called  by  either  name,  which  at  once  convey 
it  into  the  blood ; — but  being  offensive  and  injurious  to  the  body,  ano- 
ther set  of  vessels  discover  the  presence  of  the  unwelcome  visitor,  and 
speedily  go  to  work  to  throw  it  out  of  the  system.  In  the  case  of  mercu- 
ry, it  is  eonveyedout  at  the  mouth,  and  the  great  flow  of  saliva,  which 
keeps  up  a constant  spitting,  is  nothing  more  than  nature’s  scheme  to 
wash  away  the  noxious  matter. 

These  absorbents  sometimes  suck  in  a poisonous  matter;  — here 
an  action. at  once  takes  place,  of  an  extraordinary  character.  It 
seem  as  though  the  lymphatic  thus  loaded,  was  conscious  of 
its  destructive  burden,  and  instead  of  allowing  it  to  flow  to  the 
next  one,  towards  the  heart,  it  inflames,  bursts  open,  and  discharg- 
es its  contents  in  the  form  of  a sore.  Sometimes  this  ulceration  may 
extend  to  the  neighboring  lymphatic,  and  so  the  disease  be  propagated 
even  into  the  cavities  of  the  body.  If  a serpent’s  fang  wound  the  skin, 
the  absorbents  convey  the  venom  onward,  like  couriers,  to  head-quar- 
ters, the  heart,  whence  it  is  distributed  at  once  through  the  sys- 
em.  If  a bee  stings,  the  poison  is  ushered  along  by  the  same  organs. 

The  absorbents  are  exceedingly  active  agents,  but  so  small,  that 
their  existence  was  unknown,  a long  time  after  the  discovery  of  the 
circulation. 


9 


98 


ANATOMICAL  CLASS  BOOK. 


Name. 

Obturator  externus. 

.Arises  from 

The  obturator  ligament,  and 
half  of  the  thyroid  hole. 

Gluteus  maximus. 

The  spine  of  the  ilium,  pos- 
terior sacro  ischiatic  ligaments, 
and  os  sacrum. 

Gluteus  medius. 

The  spine  and  superior  sur- 
face of  the  ilium. 

Gluteus  minimus. 

The  outer  surface  of  the 
ilium  and  border  of  its  great 
notch. 

Pyriformis. 

The  anterior  part  of  the  os 
sacrum. 

Gemini. 

The  spine  and  tuberosity  of 
the  ischium. 

Quadratus  femoris. 

The  tuberosity  of  the  is- 
chium. 

MUSCLES  SITUATED  ON  THE  THIGH. 


Facialis,  or 

Tensor  vaginae  femoris. 

The  upper  spinous  process 
of  the  ilium. 

Sarto  rius. 

The  upper  spinous  process 
of  the  ilium. 

Gracilis. 

The  fore  part  of  the  ischium 
and  pubis. 

Rectus  femoris,  or 
Rectus  cruris. 

The  lower  spinous  process 
of  the  ilium,  and  edge  of  the 
acertabulum. 

Vastus  externus. 

The  root  of  the  great  tro- 

Vastus internus. 

chanter,  and  linea  aspera. 

The  trochanter  minor,  and 

Cruralis,  or  Cruraeus. 

the  linea  aspera. 

The  anterior  part  of  the 
lesser  trochanter. 

Semi-tendinosus. 

The  tuberosity  of  the  is- 
chium. 

Semi-membranosus. 

The  tuberosity  of  the  is- 
chium. 

ANATOMICAL  CLASS  BOOK. 


99 


Inserted  into 

The  femur  near  the  root  of 
the  great  trochanter. 

The  upper  part  of  the  linea 
aspera  of  the  femur. 

The  great  trochanter  of  the 
os  feinoris. 

The  root  of  the  great  tro- 
chanter. 

A cavity  at  the  root  of  the 
great  trochanter. 

The  same  cavity  as  the 
pyriforinis. 

A ridge  between  the  two 
trochanters. 


Use. 

To  pull  forward,  and  rotate 
the  thigh. 

To  extend  the  thigh,  and 
assist  in  its  rotatory  motion. 

To  assist  the  gluteus  maxi- 
mus. 

To  assist  the  two  former. 


To  roll  the  thigh  outward. 
To  roll  the  thigh  outward. 
To  move  the  thigh  outward. 


MUSCLES  SITUATE 

The  inner  side  of  the  mem- 
branous fascia  which  covers 
the  thigh. 

The  upper  and  inner  part 
of  the  tibia. 

The  upper  and  inner  part 
of  the  tibia. 

The  upper  and  fore  part  of 
the  patella. 

The  upper  and  lateral  part 
of  the  patella. 

The  upper  and  inner  part  of 
the  patella. 

The  upper  part  of  the  patel- 
la. 

The  upper  and  inner  part  of 
the  tibia. 

The  back  part  of  the  head 
of  the  tibia. 


ON  THE  THIGH. 

To  stretch  the  fascia. 

To  bend  the  leg  inward. 

To  bend  the  leg. 

To  extend  the  leg. 

To  extend  the  leg. 

To  extend  the  leg. 

To  extend  the  leg. 

To  bend  and  draw  the  leg 
inward. 

To  bend  the  leg. 


100 


ANATOMICAL  CLASS  BOOK. 


Fig.  45. 


Explanation  cf  Fig. 

45. 

a.  The  tensor  vag- 
inas femoris. 

b.  The  sartorius. 

c.  The  rectus  fe- 
moris. 

d.  The  vastus  ex- 
ternus. 

e.  The  vastus  in- 
terims. 

f.  The  pectinalis. 

g.  The  adductor 
longus. 

h.  The  adductor 
magnus. 

i.  The  gracilis. 

k.  Iliacus  internus. 

l.  The  anterior 
crural  nerve. 

m.  The  femoral  ar- 
tery. 

n.  The  femoral 
vein. 

1.  The  external  ep- 
igastric artery. 

2.  The  external  cir- 
cumflexa  ilii. 


Name. 

Biceps  fluxor  cruris. 


Arises  from 

The  tuberosity  of  the  is- 
chium. 

The  external  condyle  of  the 
thigh  bone. 


Popliteus. 


ANATOMICAL  CLASS  BOOK. 


101 


To  a person  unaccustomed  to  anatomical  language,  the  names  of 
the  muscles  will  undoubtedly  appear  exceedingly  unmeaning,  and 
difficult  to  pronounce.  This  is  true,  as  respects  the  pronunciation ; 
but  the  name,  in  a majority  of  cases,  is  really  expressive,  — giving 
both  origin  and  insertion.  An  example  of  this  double  office  of  the 
name,  may  be  noticed  in  stylo-glossus  — meaning  that  it  arises  from 
the  styloid  process,  and  is  inserted  into  the  tongue.  In  hyo-glossus, 
the  same  advantage  occurs : it  simply  informs  us  that  it  arises  from 
the  liyoideus , the  bone  of  the  tongue,  and  is  inserted  into  the  tongue. 
The  muscles  of  the  thigh  and  leg,  are  particularly  vexatious,  in  this 
respect,  to  a young  beginner.  However,  by  patiently  exercising  the 
mind,  in  a little  time  the  system  becomes  familiar. 

Though  one  bone  only  is  embraced  by  the  muscles  o(  the  thigh, 
the  circumference  is  vastly  greater  of  this  part  of  the  limb,  than  the 
leg.  This  depends  on  the  number  and  magnitude  of  the  muscles, 
which  pas3  over  the  fernoris,  from  the  pelvis,  to  reach  the  bones  of 
the  leg  below  the  knee  joint.  All  the  muscles  on  the  fore  part  of  the 
thigh,  come  from  the  upper  end  of  the  bone,  and  the  hip,  or  ilium, 
and  instead  of  being  at  all  devoted  to  the  service  of  the  bone  over 
whose  surface  they  run,  they  are  all  concentrated  in  the  knee  pan,  and 
therefore  belong  to  the  leg,  as  its  extensors  or  straighteners.  So 
violently  have  they  been  known  to  contract,  that  they  have  actually 
broken  the  knee  pan  into  two  pieces,  — one  half  held  by  its  ligament, 
down  to  its  place,  but  the  other,  drawn  by  the  uncontroled  energy 
of  the  muscles,  several  inches  up  the  thigh.  When  rising  from  a sitting 
posture,  the  entire  weight  of  the  body  is  raised  by  these  same  muscles; 
but  they  would  be  inadequate  to  the  task,  were  it  not  for  the  sliding 
of  the  knee  pan  up  the  thigh,  thereby  increasing  the  power,  by  re- 
moving the  fulcrum  from  the  centre  of  motion,  till  the  body  is  erect, 
when  it  slips  into  a pit,  made  by  the  meeting  of  the  ends  of  the  thigh 
and  leg  bones.  While  sitting,  the  muscles  being  at  rest,  the  knee  pan 
falls  into  the  space  between  the  ends  of  the  bones,  made  by  bending 
the  limb.  It  is  on  this  principle  that  the  sessamoid  bones  are  thrown 
in  under  the  tendons  of  the  toes,  to  increase  the  power  of  the  flexor, 
by  removing  the  centre  of  motion  further  from  the  joint.  This  is  a 
plan  of  nature’s  to  protect  the  toe,  which,  being  over  worked,  would 
be  ruined,  were  not  an  immediate  provision  made  for  increasing  its 
power  to  meet  the  exigency  of  the  case 


Inserted  into 

The  upper  and  back  part  of 
the  tibia,  forming  the  outer 
hamstring. 

The  upper  and  inner  part  of 
the  tibia. 


Use. 

To  bend  the  leg. 

To  assist  in  bending  the 
leg. 


9* 


102 


ANATOMICAL  CLASS  BOOK. 


Fig.  4G 
l 


\ 


MUSCLES  SITUATED  ON  THE  LEG. 

JYame.  Arises  from 

Gastrocnemius  externus,  or  The  internal  and  external 
Gemellus.  condyle  of  the  femur. 


ANATOMICAL  CLASS  BOOK. 


103 


Explanations  of  Fig.  46. 

a Tensor  vaginas  femoris. 

b.  Sartorius  reflected. 

c.  Rectus  reflected. 

d.  Vastus  externus. 

e.  Vastus  internus,  pulled  outward. 

f Pectinalis  reflected. 

g Adductor  longus  reflected. 

h.  Adductor  magnus. 

i Gracilis. 

lc.  Iliacus  internus. 

1.  The  anterior  crural  nerve. 

in.  The  femoral  artery. 

5.  The  arteria  profunda. 

6.  The  external  circumflex  artery. 

7.  The  internal  circumflex  artery. 

7i.  The  femoral  vein. 

o.  The  cruralis. 

p.  The  adductor  brevis. 

q.  The  obturator  artery  and  nerve. 

o.  The  cruralis,  vel  crureus. 

p.  The  adductor  brevis. 

Were  it  not  for  the  tendons  of  the  vast  number  of  muscles  which 
slide  by  the  knee  joint,  as  remarked  in  speakingof  the  anatomy  of  the 
bones,  this  would  have  been  an  imperfect  articulation.  Behind,  the 
hamstrings  contribute,  on  either  side,  to  the  formation  of  a canal,  in 
which  the  artery,  vein  and  great  nerve  of  the  leg,  carefully  cushioned 
up  in  a quantity  of  fat,  lie  so  securely,  that  they  very  rarely  come  to 
any  injury.  One  object  of  introducing  Fig.  45,  opposite,  was  to 
show  the  general  relation  of  some  of  the  blood  vessels, — the  nerve 
that  supplies  the  fore  part  of  the  thigh,  and  to  exhibit  the  muscles 
already  shown  in  a preceding  figure,  differently  displayed,  which 
have  such  a bearing  on  the  anatomy  of  the  joint.  Several  of  the 
long  ones  are  divided,  in  order  to  give  a clearer  view  of  those  which 
would  otherwise  be  too  much  hidden,  to  be  understood.  The  sarto- 
rius  or  tailor’s  muscle,  so  called  because  it  crosses  the  legs,  is  marked 
c — the  upper  portion  being  taken  away  to  show  i,  the  gracilis. 
In  nearly  all  operations  on  the  artery  of  the  thigh,  the  surgeon  is 
guided  by  the  edge  of  the  sartorius  — a sure  index  ; it  also  contrib- 
utes to  the  lateral  security  of  the  knee. 


MUSCLES  SITUATED  ON  THE  LEG. 

Inserted  into  Use. 

The  os  calcis,  with  the  To  extend  the  foot, 
tendon  of  the  soleus. 


104 


ANATOMICAL  CLASS  fiOOR. 


J\'nme.  Jlrises  from 

Gastrocnemius  internus,  or  The  head  of  the  fibula,  and 

back  part  of  the  head  of  the 
tibia. 

The  outer  condyle  of  the  os 
femoris  and  capsular  ligament. 


Soleus. 
Plantaris. 


Fig.  47. 


Fig.  48. 


ANATOMICAL  CLASS  BOOK. 


105 


Inserted  into  Use. 

The  os  calcis,  by  a common  To  extend  the  foot, 
tendon,  which  is  called  tendo 
Jt  chilis. 

The  os  calcis,  near  the  To  assist  in  extending  the 
tendo  Achilis.  foot. 

Explanations  of  Fig.  47. 

h.  The  tibialis  antieus. 

i.  The  extensor  longus  digitorum. 
k.  The  peroneus  tertius. 

/.  The  extensor  longus,  or  proprius  pollieis. 

m.  The  extensor  digitorum  brevis. 

n.  The  peroneus  longus. 

o.  The  peroneus  brevis. 

p.  The  annular  ligament. 


Explanations  of  Fig.  4S. 

h.  The  tibialis  antieus. 

i.  The  extensor  longus  digitorum. 

1.  The  extensor  longus  pollieis. 

q.  The  anterior  tibial  artery. 

r.  The  anterior  tibial  nerve. 


A similar  provision  is  made  in  the  leg  for  keeping  the  muscles 
down  to  their  proper  places,  that  has  been  noticed  in  the  fore  arm. 
Those  bands,  called  annular  ligaments,  which  encircle  the  ankle,  to 
prevent  the  tendons,  as  they  run  upon  the  top  of  the  instep,  from 
flying  out  from  the  bones,  in  a high  state  of  contraction,  must  excite 
admiration.  This  they  have  a constant  tendency  to  do.  If  a 
person  is  walking  up  a flight  of  stairs  on  his  toes,  he  will  then  per- 
ceive the  strong  action  of  the  tendons,  and  the  reaction  of  the  liga- 
ments upon  them.  All  those  animals  which  climb,  as  squirrels, 
monkeys,  bears,  and  some  others,  have  the  fascia  or  limb  cases, 
much  thicker,  in  proportion  to  the  size  of  the  body,  than  in  man. 
All  the  tendons  of  the  toes  and  fingers  are  bound  down  to  the  bones 
by  inelastic  bands,  — in  a similar  manner.  Birds,  particularly  those 
that  roost,  have  a beautiful  web  of  ligementarv  threads  woundround 
the  leg,  just  above  the  toes,  for  restraining  the  tendons. 

Fig.  46,  displays  an  intricate  mass  of  muscles,  originating  between 
the  upper  extremities  of  the  leg  bones.  For  nearly  a foot  below  the 
knee,  it  is  difficult  to  designate  one  from  the  other,  on  account  of  the 
intermingling  of  the  fibres.  However,  the  tendons  of  each,  are  distinct. 
No  important  vessels  or  nerves  are  exposed  on  the  skin  : — on  the 
opposite  side,  however,  they  are  to  be  found,  safely  protected  by 
muscles,  bones  aqd  fascia. 


106 


ANATOMICAL  CLASS  BOOK. 


Name. 
Tibialis  anticus. 

Tibialis  posticus. 


Arises  Jrom 

The  upper  and  fore  part  of 
the  tibia. 

The  back  part  of  the  tibia, 
interosseous  ligament,  and  ad- 
jacent part  of  the  fibula. 


Fig.  49.  Fig.  50. 


ANATOMICAL  CLASS  BOOK. 


107 


Inserted  into  Use. 

The  os  cuneiforme  inter-  To  bend  the  foot, 
num. 

The  middle  cuneiform  bone,  To  move  the  foot  inward, 
and  upper  part  of  the  os  navi- 
culare. 

Explanations  of  Fig.  49. 

q.  The  plantaris. 

r.  The  popliteus. 

s.  The  soleus. 

t.  The  biceps,  forming  the  outer  hamstring. 

u.  u.  The  semitendinosus  and  semimembranosus,  forming  the  in- 
ner hamstring. 


About  the  knee  and  ankle  joints,  professional  bone-setters  have 
played,  and  are  still  playing,  a high  handed  game  of  quackery  and 
imposition.  On  that  account,  therefore,  it  has  been  an  important 
object,  to  embody  as  much  general  information,  in  relation  to  the 
anatomy  of  the  lower  limbs,  as  possible,  and  at  the  same  time  avoid 
writing  a professional  essay  on  the  diseases  and  incidents  to  which 
they  are  particularly  predisposed.  Three  bones,  only, enter  into  the 
composition  of  the  knee  joint ; yet  in  this  land  of  common  sense,  indi- 
viduals injure  the  articulation,  and  have  it  made  well,  by  the  reduc- 
tion of  six  or  seven  ! The  ankle  joint,  made  up  entirely  of  three 
bones,  — is  often  cured  by  having  several  little  bones  thrust  into 
place  1 

In  the  immediate  neighborhood  of  these  joints,  a multitude  of 
tendons  have  been  seen,  in  the  preceding  diagrams,  on  which  their 
perfection  depends.  By  a thousand  accidents  to  which  they  are  ex- 
posed, the  tendon  of  a particular  muscle  may  be  so  prodigiously 
strained  as  finally  to  become  inflamed.  No  pain  is  more  severe  nor  more 
tedious  in  point  of  duration,  than  sprains  — or  over  stretching  of  the 
tendons  and  ligaments.  Though  slow  to  feel,  — when  once  roused, 
they  are  as  difficult  to  manage  as  the  bones,  because  they  possess  a 
vitality  so  low  and  so  far  removed  from  the  sensibility  of  the  soft 
parts,  that  remedies  are  a long  time  in  effecting  a restoration.  To  an 
inflammation  therefore,  and  not  to  the  out-of-joint  condition  of  the  little 
bones,  is  to  be  imputed  the  cause  of  protracted  lameness  in  a majority 
of  cases.  The  metatarsal  bones  of  the  instep  are  not  thrown  out  of 
place  once  in  a hundred  instances  where  it  is  supposed  they  are. 
To  youth,  these  remarks  are  addressed. 


108 


ANATOMICAL  CLASS  BOOK. 


Name. 

Peroneus  longus. 


Peroneus  brevis. 

Extensor  longus  digitorum 
pedis. 

Extensor  proprius  pollicis 
pedis. 

Flexor  longus  digitorum 
pedis,  profundus,  persorans. 


Arises  from 

The  head  of  the  tibia,  and 
upper  and  outer  part  of  the 
fibula. 

The  outer  and  fore  part  of 
the  fibula. 

The  upper  part  of  the  tibia, 
interosseous  ligament,  and  in- 
ner edge  of  the  fibula. 

The  upper  and  fore  part  of 
the  tibia. 

The  upper  and  inner  part 
of  the  tibia. 


Flexor  longus  pollicis  pedis.  A little  below  the  head  of 

the  fibula. 


Fig.  51. 


Explanations  of  Fig.  51. 
f The  external  plantar  artery. 

g.  The  internal  plantar. 

h.  The  tendon  of  the  flexor  longus  pol- 
licis. 

i.  The  tendons  of  the  flexor  longus. 
digitorum. 

j.  j.  The  massa  carnea  Jacobi  Sylvii. 

k.  k.  k.  The  lumbricales. 


MUSCLES  CHIEFLY  SITUATED  ON  THE  FOOT. 

Extensor  brevis  digitorum  The  upper  and  anterior  part 
pedi3.  of  the  os  calcis. 

Flexor  brevis  digitorum  pe-  The  lower  part  of  the  os 
dis,  perforatus  sublimis.  calcis. 


ANATOMICAL  CLASS  BOOK. 


109 


Inserted  into 

The  metatarsal  bone  of  the 
great  toe. 

The  metatarsal  bone  of  the 
little  toe. 

The  first  joint  of  the  small 
toes  by  the  four  tendons. 

The  convex  surface  of  the 
bones  of  the' great  toe. 

The  last  bones  of  all  the 
toes,  except  the  great  toe,  by 
four  tendons. 

The  last  bone  of  the  great 
toe. 


Use. 

To  move  the  foot  outward. 

To  assist  the  peroneous 
longus. 

To  extend  the  toes,  and 
separate  them  from  one  ano- 
ther. 

To  extend  the  great  toe. 

To  bend  the  last  joint  of 
the  toes. 

To  bend  the  great  toe. 


Notwithstanding  the  multitude  of  bands,  muscles,  cords  and  ves- 
sels, were  it  not  for  the  broad  sheet  in  the  sole  of  the  foot,  reaching 
from  the  heel  to  the  roots  of  the  toes,  like  the  sole.of  a shoe,  all  the 
parts  we  have  been  considering  would  have  been  inadequate  to  its 
security.  The  plantaris,  the  name  of  this  ligament,  binds  the  arch 
of  the  foot,  and  effectually  prevents  the  bones  from  being  spread 
apart,  and  at  the  same  time  constitutes  a firm  external  defence  for 
the  muscles,  nerves  and  vessels.  A similar  broad  ligament  exists  in 
the  palm  of  the  hand,  for  the  same  purpose. 


MUSCLES  CHIEFLY  SITUATED  ON  THE  FOOT. 


The  first  bone  of  the  great 
and  other  toes,  except  the 
little. 

The  second  phalanx  of  each 
of  the  small  toes,  by  four  ten- 
dons, which  are  perforated  by 
those  of  the  flex.  long.  dig. 
ped. 


To  extend  the  toes. 

To  bend  the  second  joint  of 
the  toes. 


10 


110 


ANATOMICAL  CLASS  BOOK. 


Name. 

Lumbricales  pedis. 

Flexor  brevis  pollicjs  pedis. 

Abductor  pollicis  pedis. 
Abductor  pollicis  pedis. 

Abductor  minimi  digiti  pe- 
dis. 

Flexor  brevis  minimi  digiti 
pedis. 

Transversales  pedis. 
Interossei  pedis  interni.  ^ 
Interossei  pedis  externi.  3 


Arises  from 

The  tendons  of  the  flexor 
longus  digitorum  pedis. 

The  fore  part  of  the  os  cal- 
cis,  and  external  cuneiform 
bone. 

The  inner  and  lower  part 
of  the  os  calcis. 

The  ligament  extended  from 
the  os  calcis  to  the  os  cuboi- 
des. 

The  tuber  of  the  os  calcis, 
and  metatarsal  bone  of  the 
little  toe. 

The  root  of  the  metatarsal 
bone  of  the  little  toe. 

The  ligament  connecting 
the  bones  of  the  tarsus. 

The  metatarsal  bones. 


Fig.  52. 


Explanations  of  Fig.  52. 

l.  The  plantar  arch, 

m.  The  flexor  brevis  pollicis. 

71.  The  adductor  pollicis. 

o.  The  flexor  brevis  minimi  digiti. 

p.  The  transversalis  pedis. 

q.  The  interossei. 

r.  The  long  ligament  of  the  calcis.' 

s.  The  tendon  of  the  peroneus  longus. 


ANATOMICAL  CLASS  BOOK. 


11] 


Inserted  into 

The  tendinous  expansion  at 
the  upper  part  of  the  toes. 

The  first  joint  of  the  great 
toe,  by  two  tendons. 

The  first  joint  of  the  great 
toe. 

The  outer  sesamoid  bone, 
or  first  joint  of  the  great  toe. 

The  first  joint  of  the  little 
toe  externally. 

The  root  of  the  first  bone  of 
the  little  toe. 

The  tendon  of  the  adductor 
pollicis. 

The  metatarsal  bones. 


Use. 

To  draw  the  toes  inward. 

To  bend  the  first  joint  of 
the  great  toe. 

To  move  the  great  toe  from 
the  rest. 

To  draw  the  great  toe 
nearer  to  the  rest,  and  to 
bend  it. 

To  draw  the  little  toe  out- 
ward. 

To  bend  the  little  toe. 

To  contract  the  foot. 

To  draw  the  smaller  toes 

towards  the  great  toe,  and 

assist  in  extending  the  toes. 


112 


ANATOMICAL  CLASS  BOOK. 


QUESTIONS. 


Where  are  the  ligaments  found  ? 

What  is  Syndesmology  ? 

Have  the  ligaments  sensibility  ? 

Are  they  elastic  ? 

Are  there  ligaments  within  the  skull  ? 

What  prevents  the  bones  of  the  foot  from  separating',  when 
we  stand  ? 

What  do  you  understand  by  Myology. 

What  is  a muscle ? 

What  are  the  characteristics  of  a muscle. 

Their  use  ? 

What  makes  them  red  ? 

Have  they  nerves  ? 

Are  they  all  of  the  same  figure  ? 

How  do  muscles  act  ? 

How  are  muscles  divided? 

Where  are  the  involuntary  muscles  found  ? 

Why  does  it  require  practice  to  play  musical  instruments? 
Have  the  muscles  a vitality  which  survives  the  death  of  the 
nerves  ? 

Has  each  muscle  an  antagonist  ? 

Are  they  ever  relaxed? 

Ho  they  ever  become  weary  ? 

What  is  contractility,  as  applied  to  the  muscle  ? 

What  are  tendons? 


ANATOMICAL  CLASS  BOOK. 


113 


Where  are  they  found  ? 

In  cases  of  suspended  animation,  through  the  agency  of 
what  organs  is  vitality  recalled  ? 

How  many  muscles  are  there  ? 

Are  muscles  always  in  pairs  ? 

How  many  muscles  from  the  elbow  to  the  fingers  ? 

What  muscle  raises  the  whole  arm  to  a horizontal  posture  ? 
What  muscle  surrounds  the  eye,  within  the  eyelids  ? 

Has  the  nose  any  muscles? 

Are  there  muscles  connected  with  the  external  ear  P 
What  muscles  bend  the  head  forward,  as  in  bowing? 

What  muscles  assist  us  in  walking  ? 

What  muscles  are  in  action,  in  sounding  the  vowels  ? 

What  muscles  sustain  the  upright  position  of  the  back  ? 
What  muscles  extend  the  fore  finger? 

What  muscle  bends  the  fore  arm  on  the  arm  ? 

What  is  the  fascia  and  its  use  ? 

What  muscle  is  the  longest  in  man  ? 

Are  there  muscles  in  the  tongue  ? 

Do  muscles  have  any  agency  in  modulating  the  tones  of  the 
voice  ? 

By  how  many  muscles  is  the  eye  moved  in  its  socket  ? 

What  muscle  rolls  the  eye  downward,  towards  the  shoulder  ? 
What  muscle  lies  over  the  back  of  the  neck,  like  a tippet  ? 
What  muscle  extends  the  whole  fore  arm? 

What  muscle  rolls  the  fisre  arm  to  and  fro  ? 

What  muscles  constitute  the  calf  of  the  leg  ? 

Where  do  the  flexois  of  the  toes  run,  to  reach  them  ? 

What  muscle  enables  us  to  blow  with  the  mouth  ? 


10* 


114 


ANATOMICAL  CLASS  BOOK. 


APPARATUS  OF  JOINTS. 

OR  BURSOLOGY. 

Within  the  joints  or  in  their  immediate  vicinity,  there 
are  small  sacs,  containing  a glairy,  oily  fluid,  which  is 
poured  out  between  the  articulating  surfaces,  to  prevent 
friction  ; the  name  of  this  substance  is  synovia.  Upon  the 
same  principle  that  any  machinery  is  kept  oiled,  the  joints 
arc  lubricated.  When  the  secretion  of  the  synovia,  is  im- 
perfect, or  scantily  effused  into  the  joint,  the  highly  polish- 
ed surfaces  of  the  cartilages  become  rough,  dry  and  sub- 
sequently inflamed. 

Even  in  the  sheaths  of  the  tendons,  these  oil  bags  are 
considerably  numerous.  About  the  wrist,  elbow,  shoulder, 
hip,  knees,  and  ankle,  they  are  large,  but  of  various 
shapes,  according  to  the  space  afforded  them.  Where  the 
most  motion  is  required,  there  are  the  largest  sacs,  secret- 
ing and  throwing  into  the  place,  a copious  quantity  of 
the  oil.  A disease  of  the  bursa;  mucosa;,  which  is  the 
scientific  name  of  the  sacs,  is  familiarly  known  as  the 
white  swelling,  — particularly  of  the  hip  and  knee. 

It  would  not  be  profitable  in  a simple  elementary  trea- 
tise to  dwell  minutely  on  this  subject.  The  few  observa- 
tions here  made,  will  satisfy  the  inquirer,  that  the  care 
which  is  everywhere  displayed  in  animal  mechanism,  de- 
monstrates in  the  most  happy  and  unobjectionable  man- 
ner, the  contrivance  of  a Being  antecedent  and  superior 
to  ourselves. 


ANATOMICAL  CLASS  BOOK. 


115 


FLUIDS,  OR  AN  GIOLOGY, 

THE  HEART  AND  CIRCULATION  OF  THE  BLOOD. 

It  is  one  of  the  most  curious  facts  in  the  whole  range  of 
physiological  science,  that  the  ancients  were  totally  igno- 
rant of  the  circulation  of  the  blood. 

By  a long  course  of  observations,  it  was  commonly  ad- 
mitted that  there  were  in  man,  for  example,  two  sets  of 
tubes,  which  coursed  through  the  body,  and  they  assigned 
to  each  many  absurd  and  ridiculous  functions. 

As  one  set  of  vessels  were  superficial,  directly  under  the 
skin,  filled  with  the  venous  blood,  which  quietly  moved 
along  the  smooth  duct,  — from  some  unknown  point,  to 
another,  equally  obscure,  they  were  fully  satisfied  that  it 
belonged,  in  some  way,  to  the  body.  On  the  other  hand, 
by  various  accidents,  they  had  frequent  opportunities  of 
viewing  the  deeper  seated  vessels,  throbbing  and  getting 
blood  in  recent  wounds:  — but  as  the  color  of  their  con- 
tents was  different  from  that  in  the  veins,  and  the  activity 
that  was  manifested  by  these  tubes,  when  exposed  to  their 
astonished  vision,  altogether  different  from  the  motionless, 
well  behaved  veins,  the  idea  was  at  once  admitted  that 
these,  which  were  denominated  arteries,  constituted  the 
laboratory  of  thd  animal  spirits,  — or,  in  other  words,  it 
was  in  the  arteries  that  the  powers  of  the  soul  were  gene- 
rated, in  combination  with  atmospheric  air,  which  found 
its  way  into  the  reservoirs  of  life,  through  the  puffing  and 
blowing  exercises  of  the  lungs.  When  the  artery  was  cut, 


116 


ANATOMICAL  CLASS  BOOK.' 


and  the  warm  blood  was  forced  out  by  strong  pulsations, 
then  the  spirit  within  was  angry,  — and  so  vented  its 
displeasure  and  spite,  like  a snarling  child,  by  spirting 
out  its  own  precious  self  through  the  incidental  aperture. 

Upon  notions  as  rational  as  these,  learned  men  con- 
structed some  of  the  strangest  theories  that  ever  beset  the 
imagination.  When  the  whole  subject  of  the  use  of  the 
arteries  and  veins  were  supposed  to  be  clearly  understood, 
those  sage  investigators  of  the  sublime  and  beautiful, 
rested  from  the  weight  of  their  labors,  and,  subsequently, 
established  certain  doctrines,  which  held  a despotic  sway 
for  centuries ; yet  they  were  as  far  from  truth,  as  possible, 
— and  worse  than  all,  no  person  of  common  sense  dared 
to  call  them  in  question. 

Who  but  a blockhead  would  ever  have  entertained  a 
notion  like  this,  viz.  that  the  blood  ran  out  from  the  heart 
through  the  day,  or  while  one  was  awake,  and  returned 
again  at  night,  when  the  individual  retired  to  his  slumbers  ! 
Who  but  a profound  dunce  would  have  suggested  the  novel 
theory  that  weariness , the  sensation  of  being  tired,  was  in 
consequence  of  being  so  long  awake,  that  the  blood  had 
all  run  out  from  the  fountain  head:  — and  when  one  could 
not  move  any  longer,  from  complete  exhaustion,  why  nature 
indicated  at  once  what  was  to  be  done: — only  lay  the 
poor  sufferer  on  a bed,  the  recumbent  posture  being 
highly  favorable,  the  blood  immediately  took  a downhil 
direction,  and  when  it  had  all  reached  home,  and  was 
snugly  settled  down  in  one  of  the  chambers  of  the  heart, 
the  tendency  to  death  was  suspended, — the  man  recov- 
ered his  accustomed  strength,  and  bright  and  early  the 
next  morning  the  same  truant  blood  was  ready  to  travel 
over  the  old  ground  again  ! 

Thus  it  will  be  plainly  understood,  that  the  arteries  were 
expressly  set  apart  as  a habitation  for  the  spirit  or  vital 
principle  : the  veins,  because  they  were  less  noble,  were 


ANATOMICAL  CLASS  BOOK. 


1 17 

on  the  outside,  while  the  others  within,  were  exclusively 
appropriated  to  the  to  and  fro,  night  and  morning  cir- 
culation of  the  blood. 

Another  discovery,  equally  surprising,  and  in  exact 
keeping  with  the  foregoing  arrangement,  related  to  the 
heart.  They  saw  a little  thing  carefully  boxed  up  in  the 
chest,  between  the  right  and  left  lung,  which  to  all  intents 
and  purposes  satisfied  the  student  of  nature,  that  it  was 
very  hot,  or  it  would  not  have  been  confined  and  sur- 
rounded by  two  great  bags  of  wind  : — it  was  kept  tolera- 
bly cool  by  constant  respiration  ! 

The  heart  being  decidedly  a hot  affair,  there  was  a grand 
field  for  exclaiming  and  proclaiming  the  wisdom  of  nature, 
in  providing  such  a delicate  and  at  the  same  time  simple, 
but  perfect  contrivance  for  keeping  down  its  temperature 
below  the  boiling  point ! It  was  laced  up  in  a straight 
jacket,  — the  pericardium,  vulgarly  called  heart-case,  of  a 

fpYl  n»  Q o/~»  firm  , tfinl  it  wrnc  no  cDlfimn^ont  ap  .tkat  tlio  oarlli 

was  the  centre  of  the  solar  system,  that  this  organ  was  liable 
to  prodigious  paroxysms  of  rage,  and  would  burst  from  its 
prison,  were  it  not  thus  secured.  Two  points  were  thus 
satisfactorily  settled  : viz.  that  it  was  very  hot,  and  very 
unruly. 

Again, — within,  there  were  certain  apartments,  which 
took  the  sensible  and  significant  names  of  auricles  and 
ventricles,  — because  the  walls  of  the  one  bore  some  fanci- 
ful resemblance  to  the  ears  of  a dog — but  which,  by  the 
way,  bear  just  as  much  resemblance  to  the  horns  of  the 
new  moon  ; and  in  these  cavities  certain  curious  opera- 
tions were  going  on,  which  none  but  very  wise  philoso- 
phers understood.  These  consisted  in  the  mixing  of  air 
and  blood,  — the  instantaneous  development  of  certain 
matters  and  things  which  constituted  life,  and  gun-powder- 
like  explosions,  consequent  upon  the  ingress  of  cold  air  in 
the  furnace  of  the  heart. 


118 


ANATOMICAL  CLASS  BOOK. 


In  reality,  had  those  investigating  geniuses  of  the  olden 
time,  whom  it  is  so  fashionable  to  admire,  so  classical  to 
praise,  known  anything  of  the  modern  properties  of  the 
steam-engine,  it  is  altogether  probable  they  would  have 
had  much  to  say  on  the  heart’s  property  of  generating 
power  by  converting  its  liquid  contents  into  vapor,  and, 
in  the  sequel,  laboriously  explained  the  causes  which  oc- 
casionally oppressed,  — which  clogged  the  wheels  of  vital 
action,  and  which,  in  plainer  language,  sometimes  burst 
the  boiler. 

We  have  merely  sketched  an  outline  of  the  general 
views  which  were  entertained  of  the  physiology  of  the  sys- 
tem by  the  ancients  ; — views  it  would  seem,  so  absurd  that 
the  reflections  of  a school-boy  would  have  overturned  them  : 
yet,  strange  as  it  now  appears,  they  were  carefully  trans- 
mitted from  one  generation  to  another,  for  many  centuries, 
and  treasured  up  as  the  profound  discoveries  of  antiquity. 

THE  HEART. 

It  would  seem,  at  first  view,  from  the  high  office  of  the 
heart,  so  constantly  found  in  all  animals  with  which  we 
are  familiar,  that  no  organized  being  could  possibly  exist 
without  it.  Strange,  however,  as  it  may  appear,  there 
are  various  classes,  in  the  lowest  orders  of  animal  crea- 
tion, which  are  totally  destitute  of  it;  still,  they  have  blood, 
and  that  can  under  no  circumstances  be  dispensed  with, — 
but  is  not  propelled  by  one  single  organ  through  the  ves- 
sels. There  is  a compensation,  however,  in  the  structure 
of  the  primitive  vessels, — or  to  be  understood,  a blood- 
vessel takes  upon  itself  all  the  functions  of  a heart,  ex- 
erting by  successive  pulsations,  a power  adequate  to  the 
physical  requirements  of  the  body  in  which  it  is  found. 

Numerous,  indeed,  are  the  insects  and  vermin,  in 


ANATOMICAL  CLASS  BOOK. 


119 


which  this  kind  of  organization  is  discoverable.  But  it 
is  not  an  organization  favorable  to  longevity,  for  those  in 
which  this  simple  apparatus  exists,  are  the  beings  only  of 
a day ; they  flit  in  the  sunshine  a few  hours;  the  object 
of  their  creation  is  attained,  and  they  die. 

A resemblance  to  this  sort  of  machinery  is  noticed  in 
fishes;  though  they  have  a heart,  it  is  exceedingly  imper- 
fect, when  compared  to  the  same  organ  in  warm-blooded 
animals. 

Fig.  53. 


Explanation  of  Fig.  53. 

A.  A.  are  the  fringes  of  the  gills,  attached  to  half  hoops  ot  cartil- 
age. These  threads,  which  are  of  a bright  red,  are  the  extreme 
terminations  of  the  branchial  arteries ; in  an  animal  breathing  air,  — 
the  same  vessels  are  called  bronchial  arteries. 

B.  the  ventricle  of  the  heart,  or  forcing-pump,  which  drives  the 
blood  with  which  it  is  distended,  into  a single  artery.  Just  beyond 
B,  the  artery  D divides  into  two  branches,  leading  to  the  gills  on 
either  side,  in  equal  quantities.  Precisely  like  this,  is  the  right 
heart  of  man.  Instead  of  being  thrown  into  gills,  the  branches  di- 
rect the  blood  into  the  lungs.  C,  the  auricle,  or  first  receiving  cav- 
ity of  the  heart.  All  the  veins  of  the  body  in  all  animals,  whether 
belonging  to  the  land  or  water,  ultimately  unite  into  one  tube,  and 
that  empties  it.s  blood  into  the  auricle. 

E.  In  this  diagram,  E is  the  branchial  vein,  of  the  right  gill  soon 
united  to  that  from  the  left  side  The  blood  has  been  changed  in  the 
gills,  where  it  was  sent  by  the  heart,  by  being  brought  in  contact 
with  the  air  in  the  water,  and  now  being  fit  for  the  purposes  of  the 
system,  is  returned  by  these  veins,  to  a great  vessel,  lying  under  the 
backbone. 

F.  This  is  the  reservoir  of  the  revitalized  blood:  — at  its  com- 
mencement in  the  gills,  it  is  like  a vein,  — but  the  main  trunk  now 
assumes  the  functions  of  an  artery,  or  indeed  a second  heart.  It 
contracts  and  propels  its  contents  over  the  body.  Here  then  is  a tube 
taking  upon  itself  the  office  of  the  left  heart  of  land-dwelling  ani- 
mals. 


120 


ANATOMICAL  CLASS  BOOK. 


Were  it  profitable,  reference  might  be  made  to  very  many  curious 
modifications  of  this  blood-propelling  apparatus,  so  positively  neces- 
sary to  the  existence  of  all  organized  beings,  in  the  oyster,  cuttle- 
fish, birds,  lizards,  serpents,  tortoises,  frogs,  tadpoles  and  some  other 
reptiles. 

Indeed,  the  fish  has  but  half  a heart.  All  their  blood,  — 
and  in  some  of  tire  huge  monsters  of  the  ocean  there  is  a 
prodigious  quantity,  — is  sent  its  rounds  by  an  artery , and 
not  by  a heart  or  any  particular  part  of  one.  Here  we 
perceive  that  a force  is  exerted  by  the  contractions  of  a 
single  vessel,  equal,  (for  it  must  he  in  sharks  of  thirty  feet 
in  length,)  to  a moderate  sized  fire-engine.  We  positive- 
ly know  it  to  he  so,  because  the  blood,  by  each  pulsation, 
is  driven  through  as  much  space  in  a giveri  time,  as  the 
water  is  thrown  by  the  piston  of  the  engine. 

In  the  mammalia,  that  is,  animals  breathing  air,  the 
heart  is  the  centre  of  the  circulation — the  point  from 
whence  the  blood  starts,  and  the  instrument  of  propulsion, 
by  which  it  is  kept  going  in  an  endless  round,  in  the  body. 
It  is  a forcing-pump,  by  which  a column  of  fluid  is  raised, 
and  an  imitation  of  its  mechanism  may  be  examined  in 
every  house  in  which  one  of  those  convenient  machines 
is  used  for  filling  tanks  in  the  upper  apartments.  One  is 
self-moving,  having  incorporated  within  ils  own  substance, 
the  wonderful  power  of  generating  physical  strength  ; while 
in  the  other,  an  extraneous  force  must  be  applied,  some- 
where, to  put  it  in  motion. 

Surely  the  most  sceptical  must  acknowledge  in  this  in- 
stance, and  it  is  only  one  of  many  millions  which  might 
be  cited,  that  the  work  of  an  Almighty  Being  is  here  most 
certainly  manifested.  How  simple  the  contrivance,  yet 
how  astonishing  the  results! 

In  warm-blooded  animals,  the  heart  is  a compound  en- 
gine. If  we  go  back  to  the  fishes  it  is  there  single  ; but 
in  man,  quadrupeds  and  birds,  it  is  double  : they  have  two 
hearts,  and  both  of  them  are  forcing  pumps.  Man  has 


ANATOMICAL  CLASS  BOOK. 


121 


two  hearts,  but  they  occupy  less  room  by  being  joined  to- 
gether, though,  for  aught  we  can  discover,  the  system 
could  be  just  as  well  supported,  had  one  of  them  been 
placed  at  one  side  of  the  chest,  and  the  other  at  another 
part.  By  being  united  less  substance  is  required  ; sym- 
metry is  preserved,  and  the  union  of  the  two  actually  con- 
duces to  the  greater  muscular  power  of  both. 


Fig.  54. 


Explanation  of  Fig.  54. 

By  this  engraving,  the  reader  will  readily  understand  what  we 
mean  by  the  two  hearts  of  man,  and  other  warm-blooded  animals,  as 
they  are  here  exhibited,  and  as  they  appear  when  dissected  apart. 
Each  one  of  them  is  a perfect  organ,  by  itself,  and  the  one  is  per- 
fectly independent  of  the  other.  That  having  the  letter  b upon  it, 
is  the  right  heart,  — and  that  with  a g,  the  left.  This  is  a front 
view,  or  like  looking  into  the  chest  of  another  person.  The  right 
heart  is  the  engine  of  the  lungs,  — for  it  supplies  those  organs  ex- 
clusively. The  left  heart  throws  the  blood,  as  already  remarked  in 
the  text,  round  the  curve  above  g,  in  the  direction  indicated  by  the 
arrows,  over  the  entire  body. 

a a are  the  cavas,  or  great  veins,  — returning  blood  from  the 
head  and  arms,  and  lower  extremities.  The  uppermost  is  the  su- 
perior vena  cava,  and  the  one  below,  the  inferior  vena  cava.  The 
arrows  show  the  direction  of  the  returning  currents  of  venous  blood, 
to  6,  the  auricle,  which  forces  it  into  c,  the  ventricle,  which  again 
forces  it  up  into  a,  the  pulmonary  artery,  where  it  divides,  to  go  to 
each  lung  ; e,  is  one  of  the  four  pulmonary  veins,  which  convey  the 
hlood  just  forced  into  the  lungs,  into  the  auricle  f,  of  the  left  heart. 
When  that  contracts,  it  drives  its  blood  into  g,  the  ventricle,  which, 
in  its  turn,  forces  it  onward  again  into  the  arch,  or  the  aorta,  the 

11 


122 


AN  ATOMIC  All  CLASS  BOOK. 


main  pipe,  where  it  glides  along  in  the  direction  of  the  arrow,  di- 
viding into  smaller  streams  on  its  way,  and  finally  goes  down  the 
descending  aorta  h,  to  supply  the  body  below. 

There  are  many  animals  which  have  only  the  right  heart,  but 
none  that  possess  the  left  one  alone.  The  fishes  heart,  in  the  plan 
preceding  this,  is  the  single,  equivalent  to  the  right  heart  of  man. 

That  there  might  be  no  interference,  no  irregularity, 
but  perfect  order  and  harmony,  only  one  acts  at  a time. 
The  right  heart  rests  while  the  left  moves,  and  then,  in 
perfect  obedience  to  a law  which  cannot  be  explained, 
operates  in  its  turn. 

In  configuration,  the  heart  has  no  such  vulgar  shape  as 
we  are  told  in  some  of  the  books,  like  the  ace  of  hearts 
on  a playing  card.  It  is  a short  cone,  lying  obliquely 
across  the  breast,  the  point  of  which  beats,  when  in  an 
erect  posture,  between  the  sixth  and  seventh  ribs  of  the 
left  side. 

Within,  there  are  four  apartments,  so  irregularly  shap- 
ed, that  they  cannot  be  likened  to  anything.  Each  heart 
has  its  two  cavities,  communicating  with  each  other  by 
an  orifice,  about  an  inch  in  diameter,  but  a complete  valve 
is  suspended  on  the  margin  of  the  opening,  like  a gate, 
to  close  it,  that  all  communication  may  be  instantaneously 
interrupted,  as  we  shall  ascertain  to  be  indispensably 
necessary,  at  each  pulsation.  Moreover,  to  prevent  the 
heart  from  ever  being  over  distended,  from  having  its  walls 
put  too  much  upon  a stretch,  little  cords  of  astonishing 
tenacity,  run  from  one  side  to  the  other  crossing  and  re- 
crossing each  other  in  all  directions,  which  also  assist,  by 
contracting,  to  squeeze  it,  as  it  were,  together,  in  forcing 
out  its  contents. 

To  secure  it  still  farther,  guarding  against  all  contin- 
gencies, the  heart  is  enveloped  in  a tough,  slightly  elastic 
case.  Having  this  support,  were  the  internal  straps  to  be 
rent  from  their  attachments,  the  swelling  heart  would  be 
met  from  without,  by  its  covering,  and  prevented  from 
being  ruptured  by  the  accumulation  of  the  blood  within. 


ANATOMICAL  CLASS  BOOK. 


123 


Lastly,  that  the  freedom  of  motion  might  never  be 
abridged,  the  heart  is  suspended  at  the  top  of  the  chest,  by 
its  own  lubes,  being  at  liberty  to  swing  in  the  triangular 
space  given  it  between  the  lobes  of  the  lungs,  according 
to  the  various  attitudes  the  body  assumes.  This  is  not 
all  ; the  heart  constitutes  a hollow  muscle,  being  as  com- 
pletely flesh  as  the  muscles  of  the  arm.  Besides,  it  pos- 
sesses all  the  essential  characteristics  of  every  muscle,  the 
inherent  property  of  contractility. 

Having  explained  the  fact  that  there  are  two  hearts,  it 
is  now  necessary  to  show  the  necessity  of  this  arrange- 
ment, which  is  no  easy  matter,  inasmuch  as  we  are  to 
adapt  our  demonstration  to  the  capacity  of  the  young. 

Throughout  the  system  there  are  two  sets  of  tubes  for 
conveying  blood  ; — one  conducting  it  through  the  body, 
and  the  other  returning  it.  To  be  serviceable  to  the 
system,  which  is  the  final  cause  of  the  elaborate  machi- 
nery under  consideration,  two  other  important  organs  must 
necessarily  claim  attention,  viz.  the  stomach  and  the 
lungs. 

In  the  former,  the  food  is  converted  into  a milky  liquor, 
from  whence  it  is  actually  conveyed  into  one  of  the  cavi- 
ties of  the  heart ; but  before  it  can  be  of  any  service,  it 
must  first  be  mixed  with  that  already  in  the  veins.  A 
chemical  change  is  effected  in  it  by  being  exposed  to  the 
action  of  the  atmospheric  air,  that  makes  it  blood. 

As  the  first  process  is  completed,  the  next  object  nature 
has  in  view,  is  to  distribute  it,  and  the  left  heart  is  the 
apparatus  by  which  it  is  effected.  There  is  no  communi- 
cation between  the  cavities  of  the  two  hearts,  but  we  per- 
ceive that  the  blood  which  is  pouring  into  the  right  side, 
must  be  thrown  somewhere,  and  as  it  cannot  go  into  the 
left,  where,  the  query  will  arise,  does  it  move  ? — directly 
into  the  lungs.  From  thence  it  is  collected,  and  by  four 
branching  tubes  carried  to  the  left  heart.  Thus,  the  left 


124 


ANATOMICAL  CLASS  BOOK. 


heart  forces  it  in  all  directions  from  the  centre,  and  the 
l ight  heart  forces  that  which  has  been  returned  into  the 
lungs. 

By  an  untiring  labor  of  the  two  hearts,  acting  alter- 
nately, from  birth  till  death,  the  blood,  that  important  sub- 
stance, on  which  life  depends,  is  kept  always  going  and 
coming,  and  whatever  property  or  quantity  is  lost  on  the 
loute,  is  supplied  by  the  activity  of  the  stomach,  the  great 
laboratory  in  which  the  material  is  manufactured  of  which 
it  is  originally  made. 

Authors  detail  the  particulars  of  what  they  call  the 
two  circulations, — viz.  the  greater  and  lesser,  by  which  is 
to  be  understood,  that  the  right  heart  and  lungs  constitute 
this  lesser,  because  the  force  of  the  engine  is  only  exerted 
to  throw  its  contents  into  the  air  cells  of  the  lungs.  On 
the  other  hand,  the  greater  circulation,  means  the  left 
heart  and  all  the  arteries  leading  from  it,  quite  to  the  ex- 
tremities. 

As  the  power  to  be  exerted  by  the  left  heart,  in  order 
to  throw  the  blood  the  entire  length  of  the  body,  is  vastly 
superior  to  its  fellow,  which  is  only  required  to  push  its 
volume  of  blood  about  ten  inches,  so  it  is  proportionably 
stronger  in  its  substance  : thicker  in  its  walls,  and  more 
sensitive  to  the  application  of  stimuli.  In  the  act  of  dying, 
the  left  heart  invariably  clears  all  its  cavities,  — and  there- 
fore is  always  empty  on  dissection,  but  the  right  heart  re- 
mains full  and  burthened, 


ANATOMICAL  CLASS  BOOK. 


125 


Fig.  55. 


Explanation  of  Fig.  55. 

The  double  heart  of  man  : — q,  descending  vena  cava  ; o,  ascend- 
ing vena  cava  ; n,  right  auricle  ; b,  right  ventricle  ; k,  pulmonary 
artery;  1,1,  right  and  left  branches  of  this  artery,  going  to  the 
lungs  on  either  side  of  the  chest;  m,  m,  veins  of  the  lungs,  which 
return  what  the  artery  sent  in,  to  r,  the  left  auricle  ; a,  the  left  ven- 
tricle ; c,  e,f,  aorta  or  great  artery  of  the  body,  rising  out  of  the  left 
heart;  g,  arteria  innominata  ; h,  the  subclavian  artery , going  to  the 
left  arm  ; i,  the  carotid  artery,  which  goes  up  the  side  of  the  neck 
to  the  head.  JYote  — the  arrows  show  the  course  the  blood  moves 
in  each  of  the  vessels  demonstrated  with  the  heart;  n,  right  auricle; 
m , m,  veins  of  the  lungs ; s,  left  coronary  artery.  P,  veins  returning 
blood  from  the  liver  and  bowels. 

There  is  no  essential  difference  in  the  external  appearance,  or  in- 
ternal organization  of  the  heart  of  man,  and  breathing  animals  gen- 
erally; hence,  in  a cabinet,  it  would  be  exceedingly  difficult  for  a 
practical  anatomist  to  designate  the  human,  from  the  heart  of  a'brute, 
provided  they  were  of  equal  dimensions. 

Nothing  is  easier,  than  to  fill  a heart  with  wax,  or  even  plaster 
paris,  in  order  to  exhibit,  distinctly,  all  its  vessels  and  its  exact  shape 
in  a state  of  distention.  The  heart  of  any  of  the  domestic  animals, 
procured  at  the  market  may  he  thus  filled,  and  kept  for  many  years. 

11* 


126 


ANATOMICAL  CLASS  BOOK. 


Ultimum  moriens,  the  last  part  to  die,  was  an  accurate 
remark  of  the  old  anatomists.  In  reptiles  and  fishes  s° 
irritable  is  the  heart,  — and  it  is  to  be  remembered,  they 
possess  only  one  half  of  ours,  equivalent  to  the  left  one, — 
that  long  after  the  body  is  dead,  the  heart,  separated  from 
all  its  connexions,  will  continue  to  pulsate  upon  the  table 
for  half  an  hour  ; — when  it  has  exhausted  itself,  if  it  be 
touched  with  the  point  of  a pin,  it  will  be  roused  into  ac- 
tivity again,  and  beat  and  throb  as  though  it  were  con- 
scious of  making  a desperate  struggle  for  existence. 

When  the  frog’s  heart  has  been  a whole  hour  under  in- 
spection, it  will  continue  to  pulsate,  even  by  blowing  it. 
The  mangled  body,  all  this  time  disemboweled,  shocking 
as  it  may  seem,  leaps  about  the  house,  without  a heart, 
without  blood,  and  with  lacerated  nerves  and  muscles, 
apparently  just  as  well  as  before  those  cruelties  were  com- 
menced. 

Each  heart  has  two  cavities,  as  repeatedly  remarked, — ■ 
but  for  the  sake  of  conforming  to  the  usual  method  of  de- 
scription we  will  say,  the  heart  has  four  cavities,  two  of 
which  are  the  auricles,  being  uppermost,  and  two  directly 
beneath  them,  the  ventricles. 

The  numerous  threads,  already  spoken  of,  reaching 
from  one  side  to  the  other,  are  called  cordce  tendincce,  and 
those  which  are  fleshy  in  the  middle  columnce  and  massce 
carnecE.  Their  office  is  merely  to  prevent  the  auricle  from 
being  overcharged, — acting  precisely  upon  the  principle 
of  a tape  the  manufacturer  tacks  in  to  keep  the  lid  of  a 
trunk  from  falling  open  so  far  as  to  wrench  off  the  hinges. 

From  the  lower  part  of  the  auricle,  the  opening  into  the 
ventricle  is  a smooth  round  hole,  opened  and  closed  by  a 
valve  that  springs  downward,  but  never,  in  any  instance  on 
record,  has  it  been  pushed  up  through.  The  valve  is  curi- 
ously supported  by  little  tags,  lines  and  weights  to  prevent 
its  being  pressed  by  any  force  that  might  have  a tendency 


ANATOMICAL  CLASS  BOOK. 


127 


to  press  it  the  wrong  way,  — and  at  the  same  time,  these 
accompaniments  assist  in  moulding  the  edges  precisely  to 
the  ragged  surface  of  the  border  of  the  hole,  so  that  it 
shall  be  completely  tight.  That  it  is  impervious,  may  be 
inferred  from  the  fact,  that  the  heart  has  been  repeatedly 
ruptured  by  its  own  exertion,  on  the  blood  filling  its  ventri- 
cles, or  auricles,  yet  the  strong  walls,  half  an  inch  in 
thicknesss,  gave  way,  while  the  tiny,  transparent  valve, 
maintained  its  place. 

The  strips  which  enter  into  its  composition,  being  fanci- 
fully imagined  to  be  three,  takes  the  name  of  tricusped , 
because  it  has  three  points  supposed  to  resemble  teeth. 
On  the  top  of  the  auricle,  two  or  three  large  veins  pre- 
sent their  mouths  : — one  is  the  vena  cava  superior , the 
great  trunk  which  brings  all  the  blood  from  the  head  and 
arms  into  the  reservoir;  and  another,  nearly  opposite,  is 
the  vena  cava  inferior,  in  which  all  the  blood  is  brought 
from  the  feet  and  body.  There  is  a third,  very  much 
smaller,  however,  the  coronary  vein,  returning  the  blood 
which  has  circulated  exclusively  in  the  substance  of  the 
heart.  Over  this  last  opening,  is  a crescent  shaped  valve, 
highly  important,  for  were  it  not  there,  every  time  the 
auricle  contracted,  it  would  force  the  blood  wherever  there 
was  no  resistance,  which  therefore,  instead  of  allowing  the 
venous  blood  to  return  into  the  common  fountain,  would 
be  continually  driven  onward,  so  that  the  heart  itself  would 
suffer  from  an  obstructed  circulation : this  half  moon 
shaped  valve,  swinging  downward,  entirely  opposes  the 
ingress  of  blood  from  the  auricle,  yet  freely  allows  that 
coming  from  the  heart  to  make  its  exit  by  the  valve. 

Can  we  contemplate  anything  more  purely  mechanical 
than  this  contrivance.  Can  any  one  in  his  senses  argue 
himself  into  the  absurd  belief,  that  this  peculiar  arrange- 
ment, this  striking  adaptation  of  parts,  all  concurring  to  the 


128 


ANATOMICAL  CLASS  BOOK. 


utmost  perfectablility  of  the  machine,  splendid  in  its  struc- 
ture happened  all  by  chance  ! 

The  auricle  being  filled,  — the  sense  of  fulness,  a pro- 
perty entirely  independent  of  the  mind,  wholly  beyond  the 
control  of  the  laws  of  volition,  prompts  it  to  expel  it.  This 
it  does  by  collapsing  ; by  simultaneously  contracting  all 
its  parts  upon  the  mass  within,  which  is  thereby  driven 
per  saltum,  through  the  great  canal,  down  into  the  ventri- 
cle,— the  second  apartment.  To  admit  it  there,  a pre- 
paration is  necessary  on  the  part  of  the  ventricle,  — and 
that  consists  in  relaxing  itself  to  enlarge  its  capacity  for 
receiving  the  portion  that  is  on  the  way  from  the  auricle. 
At  the  instant  of  being  filled,  the  tricusped  valve,  which 
was  before  pendulous,  flaps  back,  cuts  off  all  further  com- 
munication, and  thus  holds  all  that  has  been  admitted,  to 
be  afterwards  disposed  of. 

Because  the  auricle  is  obliged  to  make  an  effort  only 
strong  enough  to  urge  its  contents  by  the  valve,  it  is  com- 
paratively slightly  made,  and  weaker  than  the  ventricle. 

Having  the  ventricle  filled,  let  us  watch  the  process  by 
which  it  clears  itself.  It  has  been  premised,  that  its  duty 
is  to  push  the  blood  to  the  lungs,  a distance  of  about  ten 
inches,  though  if  we  suppose  that  the  extreme  ramifica- 
tions of  the  bronchial  arteries  are  gorged  by  each  throw 
of  the  ventricle,  the  power  is  equal  to  projecting  the 
stream  between  seventy  and  eighty  feet.  This  point  is 
rather  dubious ; anatomists  have  not  satisfied  themselves 
whether  the  ventricle  actually  presses  the  blood  to  the  ex- 
treme twigs  of  the  lungs,  or  only  sends  it  beyond  the 
valves  in  the  mouth  of  the  pulmonary  artery,  hardly  a dis- 
tance of  seven  inches.  Be  that  as  it  may,  the  fact  is  no- 
torious,— if  it  were  not  designed  to  exert  a force  more 
than  ten  times  as  great  as  the  auricle,  surely  it  would  not 
have  been  made  so  very  much  stronger,  and  so  amply  pro- 
vided with  materials  for  that  purpose. 


ANATOMICAL  CLASS  BOOK 


129 


If  the  auricle  can  send  a column  of  blood  ten  feet,  the 
ventricle,  by  its  additional  physical  advantages,  could 
throw  the  same  quantity  fifty  feet  in  precisely  the  same 
time.  This  looks  a little  like  being  able  to  reach  the 
lungs,  notwithstanding  the  reasonings  of  authors  to  the 
contrary.  Suffice  it,  that  when  the  stimulus  of  distention 
creates  the  exciting  sensation,  the  walls  contract,  as  in 
the  other  case,  and  every  drop  of  the  blood  goes  through 
a very  delicately  smooth,  round  hole, — the  only  outlet 
from  the  ventricle,  besides  the  place  of  entrance,  — and 
this  is  the  beginning  of  the  pulmonary  artery,  the  great 
blood  vessel  of  the  lungs.  Here  w'e  leave  the  description 
of  the  right  heart,  for  the  present,  lest  minuter  details 
should  distract,  rather  than  enlighten  those  who  may,  per- 
haps, endeavor  to  obtain  their  first  accurate  notions  of  this 
local  piece  of  anatomy,  from  our  dissertation. 

Much  as  the  heart  of  the  body,  that  on  the  left  side,  re- 
sembles the  one  before  us,  there  are  peculiarities  requiring 
a careful  and  patient  investigation,  if  we  are  desirous  of 
perfectly  comprehending  its  structure  and  interesting 
functions. 

Were  a well  prepared  specimen  of  the  heart  to  be  lying 
before  the  reader,  he  would  regard  the  general  appearance 
of  strength  in  the  left  side,  as  though  more  depended  upon 
it  in  the  economy  of  life,  than  on  its  associate.  Such 
is  truly  the  fact,  that  the  power  manifested  by  it,  is  im- 
mensely superior. 

United,  as  just  seen,  are  the  left  auricle  and  ventricle, 
with  a similar  valvular  communication  between  them. 
The  left  auricle  is  considerably  larger  than  the  right,  but 
bears  more  resemblance  to  a square  box,  in  a state  of  dis- 
tention, than  a sac.  The  entire  office  of  this  is  to  expel 
the  blood  forcibly  into  its  neighboring  ventricle.  Uniting 
by  degrees,  all  the  veins  gradually  terminate  in  four  con- 
siderable trunks,  in  the  two  sides  of  the  auricle,  nearly 


130 


ANATOMICAL  CLASS  BOOK. 


opposite  to  each  other.  Two  of  them  bring  the  blood 
from  the  right,  and  the  others  from  the  left  lobes  of  the 
lungs. 

When  the  ventricle  is  full,  let  it  be  recollected  that  it 
must  send  its  blood  in  two  directions,  viz.,  .towards  the 
head,  as  well  as  the  feet;  and  at  the  same  time,  supply  all 
the  intermediate  viscera,  muscles,  nerves,  and  even  the 
very  bones  themselves,  however  hard  or  remote  from  the 
centre  of  the  circulation.  Whether  the  ventricle  accom- 
plishes the  feat,  remains  to  be  discussed  hereafter.  By  its 
contraction,  a valve  called  the  mitral,  shuts  back  to  pre- 
vent a regurgitation,  — hence  the  blood  can  only  escape 
through  the  canal  provided  for  it.  This  is  a long,  strong 
tube,  nearly  an  inch  in  diameter,  in  man,  known  as  the 
aorta.  Directly  in  the  calibre  of  the  aorta  are  three  valves, 
so  adjusted  to  the  condition  and  shape  of  the  artery,  that 
the  three,  in  being  spread  horizontally,  (the  posture  has 
no  influence  on  the  action)  they  effectually  close  the  chan- 
nel, so  that  nothing  which  may  have  passed  the  portals, 
can  possibly  be  returned.  Thus  the  functions  of  the  two 
hearts  are  analogous;  the  principle  of  propulsion  is  the 
same,  and  indeed,  when  the  office  and  organization  of  one 
is  understood,  it  illustrates  sufficiently  tvell,  the  other. 

The  line  of  union  between  the  two,  is  termed  the  sep- 
tum cordis.  All  the  fibres  of  the  two  ventricles  have  a 
winding  direction,  which  give  the  heart  a twisting  or  ver- 
micular kind  of  motion  in  its  pulsations.  The  alternate- 
ly swelling  and  collapsing,  as  when  full,  or  empty,  are,  the 
disastole  and  systole,  terms  used  to  express  the  pulsations. 

Although  the  heart  is  the  fountain  of  life,  dispensing 
the  blood  either  directly,  or  indirectly,  to  the  smallest  twig, 
wherever  located,  in  the  body,  it  requires  a circulation  of 
the  same  vitalizing  fluid,  to  sustain  its  own  existence. 

For  this  purpose  there  are  vessels  creeping  out  at  the 
sides  of  the  aorta,  at  right  angles  with  the  trunk,  just 


ANATOMICAL  CLASS  BOOK. 


131 


above  the  semi-lunar  valves,  which  wend  their  way  direct- 
ly to  the  divisional  horizontal  line,  between  the  auri- 
cles and  ventricles,  where,  carefully  imbedded  in  a trian- 
gular depression,  out  of  the  way,  the  coronary  arteries 
are  continually  sending  off  branches  that  dip  down  into 
the  substance  of  the  heart,  supplying  it  abundantly  with 
arterial  blood.  When  it  has  completed  its  route,  and  is 
in  readiness  to  go  on  again,  to  get  within  the  cavities  of 
the  heart,  from  the  extremities  of  the  coronary  arteries, 
veins  commence,  called  coronary,  which  keep  gradually 
uniting,  and  ultimately  coalesce  in  one  single  tube,  the 
coronary  vein,  the  diameter  of  a writing  pen,  whose  mouth 
was  found,  on  examination  of  the  right  auricle,  be- 
hind a beautiful  little  coronary  valve.  In  this  way  the 
substance  of  the  heart  is  supplied  with  nutriment,  to  sus- 
tain it  in  a course  of  activity,  that  never  tires,  and  which 
never  ceases  to  palpitate,  till  death  puts  a stop  to  its 
motion. 


NERVES  OF  THE  HEART. 

These  are  few,  arising  from  the  sympathetic  and  eighth 
pair  of  nerves.  The  sympathetic , is  a kind  of  line  of  union 
receiving  a deputation  from  all  the  principal  nerves 
throughout  the  frame,  by  which  a connexion  is  maintained 
with  all  the  different  parts  of  the  complicated  whole. 
The  eighth  pair  of  nerves  arise  in  the  brain,  but  traverse 
down  the  side  of  the  neck  into  the  chest,  following  the 
course  of  the  windpipe  and  eesophagus,  quite  to  the  stom- 
ach. F rom  these,  there  being  a pair,  one  on  either  side,  fil- 
aments shoot  off  to  the  heart.  The  minutas  of  the  course 
is  not  essential.  In  this  way  the  heart  holds  a line  of 
communication  with  the  work-shop,  the  stomach,  where 
it  looks  for  the  manufacture  of  the  material  from  which 
the  blood  is  elaborated ; and  by  the  other  set  of  nervous 


132 


ANATOMICAL  CLASS  BOOK. 


cords,  it  possesses  a general  relationship  to  all  the  portions 
of  the  living  body,  which  look  up  to  it  for  a maintenance. 

Placing  the  heart  entirely  beyond  the  reach  of  the  in- 
constant, unstable  will,  was  indeed  a happy  circumstance 
in  the  economy  of  our  being.  No  one  can  put  a stop  to 
the  pulsations  of  his  heart,  in  a fit  of  despair  or  rage,  as 
thousands  would,  were  it  possible.  It  still  works  on,  by 
night  as  well  as  day,  though  the  intellect  sleeps,  — and 
thus  we  are  safely  protected.  If  the  pulsations  and  the 
maintenance  of  life,  through  the  heart’s  agency,  depend- 
ed on  our  vigilance,  how  soon  we  should  forget  the  charge, 
and  suffer  the  chronometer  of  life  to  run  down  the  first 
time  it  was  left  in  our  care.  Wisdom,  — the  manifesta- 
tions of  an  Ever  Living,  Omniscient  Deity,  are  displayed 
at  every  stage  of  anatomical  research. 

HEART-CASE,  OR  PERICARDIUM. 

An  allusion,  merely,  has  been  made  to  the  heart-case, 
or  pericardium,  the  office  and  importance  of  which  is  very 
likely  to  be  overlooked.  It  is  the  membrane  which  far- 
mers sometimes  make  money  purses  of,  on  account  of  its 
softness,  toughness  and  capacity.  In  the  chest,  lying  be- 
tween the  breast  bone  in  front  and  the  spinal  column  be- 
hind, it  is  like  a bag,  kept  on  the  stretch  by  a hoop  : on 
either  side  are  the  lungs,  confined,  however,  in  their  own 
appropriate  cavities.  A duplication  of  its  inner  coat  in- 
vests the  substance  of  the  heart,  closely,  and  on  the  sur- 
face, spread  over  the  heart,  as  well  as  from  the  inside  of 
the  pericardium,  a halitus  is  exhaled,  that  lubricates  the 
cavity,  — admitting  the  gentlest  possible  motions,  as  it 
swings  in  the  apartment.  Though  the  heart  is  moving 
about,  its  apex  being  sometimes  at  one  point,  and  some- 
times at  another,  according  to  our  position,  the  pericar- 
dium never  moves  from  its  place,  being  always  kept  upon 
the  stretch. 


ANATOMICAL  CLASS  BOOK. 


133 


Fig.  56. 


a,  the  heart,  in  its  natural  position,  the  sternum  being  taken  away, 
and  the  pericardium  laid  open,  in  front,  to  give  a full  and  perfect  view 
of  the  organ  ; c,  is  the  arch  of  the  aorta,  or  primitive  artery  of  the 
body,  from  which  all  others  arise;  e,  is  the  diaphragmatic  nerve, 
having  its  origin  high  up,  on  the  side  of  the  neck,  and  travelling 
down  into  the  chest,  on  the  outside  of  the  'pericardium,  or  heart 
case,  to  reach  the  diaphragm,  — the  partition  that  divides  the  chest 
from  the  abdomen.  If  this  nerve  is  divided,  all  motion  in  the  dia- 
phragm will  cease.  It-should  be  recollected  that  it  is  a muscle  of 
respiration, — rising  and  falling  with  the  inflation  and  collapse  of  the 
lungs.  The  base,  or  rather  underside  of  the  heart,  as  it  is  suspend- 


12 


134 


ANATOMICAL  CLASS  BOOK. 


ed  from  above,  rests  on  tbo  diaphragm  at  the  lower  b ; b,  b,  i,  the 
heart  case  ; d,  the  descending  cava,  or  great  vein  that  returns  the 
blood  from  the  head  and  arms,  into  the  right  auricle  of  the  heart. 


ARTERIES. 


To  describe  the  arteries  in  a manner  intelligible  to  per- 
sons who  have  never  examined  an  anatomical  preparation, 
in  which  these  vessels  are  distended  with  wax,  is  certainly 
a difficult  undertaking. 

Fig.  57. 


ANATOMICAL  CLASS  BOOK. 


135 


Explanation  of  Fig.  57. 

By  referring  back  to  the  plan  of  the  perfect  double  heart,  i shows 
the  origin  of  the  carotid  artery,  a branch  from  the  arch  of  the  aorta. 
In  this  very  accurate  plan  of  the  superficial  arteries  of  the  head,  a 
is  the  continued  trunk  of  the  carotid  artery  : it  is  this  vessel  which 
is  usually  divided  by  suicides  ; it  is  this  vessel  also,  with  its  mate 
on  the  other  side  of  the  neck,  which,  when  compressed,  causes  ap- 
poplexv  and  death,  f,  the  occipital  artery,  going  to  the  muscles  on 
the  back  of  the  head;  b,  is  the  larynx,  or  vocal  box;  c,  indicates 
the  place  where  the  carotid  divides  into  the  n,  the  external  carotid, 
branching  onward;  b,  also  is  the  superior  thyroid  artery;  p,  the 
thyroid  gland,  and  inferior  thyroid  artery  ; k,  the  temporal  artery, 
felt  beating  in  the  temple,  and  sometimes  selected  to  bleed  from  in 
desperate  cases  ; o , the  left  subclavian  artery ; l , the  masseter  mus- 
cle ; h,  depressor  anguli  oris,  having  running  under  it  the  external 
maxillary  artery  ; i,  the  zygomaticus  major,  directing  the  eye  also 
to  the  coronary  arteries  of  the  lips  ; q,  the  nasal  artery  ; r,  the  ter- 
mination of  the  temporal  artery,  in  minute  twigs  on  the  top  of  the 
head. 

After  all  that  is  said  about  the  catalogue  of  arteries  laid 
down  in  the  human  body,  there  is  really  but  one  artery,  all 
others  being  branches  from  it.  But  to  answer  the  purpos- 
es of  the  surgeon,  it  is  absolutely  necessary  to  treat  of 
each  twig  distinctly,  in  order  that  its  relation  to  other  parts 
may  be  impressed  on  the  mind  of  an  operator. 

This  one  artery,  the  primitive  trunk,  is  the  aorta,  rear- 
ing itself  out  of  the  left  ventricle  of  the  heart : collectively 
the  parent  tube,  with  its  subdivisions  into  thousands  of 
tortuous  pipes,  is  denominated  the  aortic  system;  and 
when  arteries  and  veins  are  spoken  of  together,  as  a whole, 
the  term  sanguiferous  system  is  used. 


i 


136 


ANATOMICAL  CLASS  BOOK. 


Fig.  58. 


Explanation  of  Fig.  58. 


This  diagram  may  be  regarded  as  perfectly  true  to  nature.  The 
design  is  to  show  how  the  blood  is  conveyed  to  deep  seated  muscles 
of  the  face,  and  to  the  membranes  covering  the  brain,  within  the 
skull:  — all  the  vessels  now  under  the  oye,  are  branches,  originat- 
ing from  the  trunk  of  the  external  carotid  artery,  shown  in  the  pre- 
ceding plan.  a.  is  the  middle  or  great  meningeal  artery  of  the  dura 
mater.  By  the  side  of  the  ear,  lies  the  trunk  of  the  internal  max- 
illary artery,  supplying  a vast  quantity  of  blood  to  the  muscles  of 
the  face;  part  of  the  jaw  and  the  process  of  the  temporal  bone  is  re- 
moved, to  explain  the  manner  of  its  course  under  and  about  them. 
h,  a branch  of  the  inferior  maxillary  artery , seen  in  the  other  plan  : 
c,  posterior  temporal  branch  ; d,  pterygoid  arteries,  supplying  those 
muscles  which  move  the  jaw,  in  chewing  ; i,  buccal  artery , going 
to  the  buccinator,  or  trumpeter’s  muscle  ; f anterior  deep  temporal 
branch  ; e,  infra  orbitar  artery. 

The  bone  in  this  figure,  is  supposed  to  have  been  taken  away,  in 
order  to  exhibit  the  arteries  a which  branch,  like  the  limbs  of  a 
tree,  over  the  surface  of  the  dura  mater. 


ANATOMICAL  CLASS  BOOK. 


J37 


As  the  great  cylinder  rises  above  the  top  of  the  heart, 
thick,  white  and  shining,  it  is  bulged  out  at  the  sides,  in 
in  three  directions,  at  the  place  where  the  three  semilunar 
valves  are  fixed.  The  enlargement  is  known  as  the  sinus 
of  Valsalvi,  from  its  supposed  discoverer.  Gradually  it  be- 
comes smaller,  preserving,  however,  a diameter  equal  to 
three  fourths  of  an  inch,  till  it  gets  above  the  heart,  where 


Fig.  59. 


Explanation  of  Fig.  59. 

This  figure  has  been  introduced  to  show  the  manner  of  supplying 
the  brain  with  arterial  blood  by  the  vertebral  arteries.  It  will  doubt- 
less be  recollected  by  the  critical  student,  that  in  the  side  arms  of 
the  vertebrae  of  the  neck,  there  were  round  holes,  from  one  bone  to 
the  other.  Through  those  holes,  an  artery  creeps  securely  into  the 
skull,  unexposed  to  the  thousand  accidents  to  which  the  carotid  ar- 
teries are  liable.  If,  for  example,  an  operation  requires  that  the 
carotids  should  be  tied,  so  that  no  blood  can  pass  in  them,  a supply 
for  the  brain  is  secured  by  these  vertebrals.  When  they  have  ar- 
rived within  the  skull,  at  the  underside  of  the  brain,  the  two  mark- 
ed 6,  b,  unite  into  one  — which  is  c,  — and  then  branches  off  among 


133 


ANATOMICAL  CLASS  BOOK. 


the  convolutions  of  the  brain,  indicated  by  the  various  letters;  g, 
is  the  little  brain  or  cerebellum ; f,  the  middle  lobe  of  the  brain,  or 
cerebrum;  e,  the  anterior  lobe  of  the  cerebrum;  and  a,  the  optic 
nerves,  or  nerves  of  vision.  This  is  no  fanciful  distribution  of  the 
arteries  of  this  organ,  but  a perfectly  true  representation. 

it  is  gracefully  curved  over  and  upon  the  spine,  down 
which  it  runs  the  entire  circuit  of  the  chest  and  abdomen. 
On  the  last  joint,  though  not  constantly,  of  the  back,  it 
divides  into  two  trunks,  to  be  sent  to  the  inferior  extremi- 
ties. On  the  highest  point  of  the  arch,  branches  shoot  off, 
to  carry  blood  to  the  head  and  arms.  Those  going  up  the 
side  of  the  neck,  are  the  carotids,  the  arteries  which 
suicides  divide  in  cutting  their  throats.  It  is  by  com- 
pressing these,  as  in  hanging,  that  death  is  produced  : — 
when  they  arrive  at  the  angle  of  the  under  jaw,  they  divide 
into  external  and  internal  carotids  : — the  deep  seated  or 
inner  ones  go  through  an  orifice  in  the  bottom  of  the  skull, 
to  supply  the  brain ; while  the  externals  creep  up  by  the 
side  of  the  ear,  face,  &c.,  supplying  all  the  muscles  and 
bones  in  the  vicinity. 


Fig.  GO. 


ANATOMICAL  CLASS  BOOK. 


139 


Explanation  of  Fig.  60. 

A very  large  quantity  of  blood,  as  we  have  seen,  is  sent  to  the 
brain,  by  four  arteries,  viz.  the  two  carotids  and  two  vertebrals.  By 
this  plan,  it  will  be  plainly  understood  how  the  blood  gets  back 
again  to  the  heart.  The  superior  longitudinal  sinus,  Fig.  1,  is 
nothing  more  than  a vein,  — of  a triangular  shape,  beginning  with- 
in the  skull,  opposite  the  root  of  the  nose,  and  going  backward,  be- 
tween the  bone  and  outer  membrane  of  the  brain,  over  the  top 
of  the  head  — increasing  in  size  as  it  goes,  till  it  reaches  the  level  of 
the  posterior  lobe,  — where  it  divides  into  two  canals,  marked  3.  3. 
Many  twigs  of  veins,  pointed  out  by  the  other  figures,  bring  the 
blood  from  other  places  in  the  head,  but  ultimately,  they  all  join  one 
or  the  other  branches  of  the  main  trunks  of  the  sinus:  3.  3.  are 
called  lateral  sinuses,  because  they  are  on  the  sides,  as  it  were  of 
the  head.  These  two  trunks  pass  through  a fissure,  in  the  under 
side  of  the  skull,  between  the  temporals  and  occipital  bone,  and  ap- 
pearing by  the  side  of  the  neck,  are  there  called  the  jugular  veins. 
The  external  jugulars  return  the  blood  from  the  face,  &c,  and  finally 
join  the  interna!  jugulars,  — and  there,  by  entering  the  chest,  be- 
come enlarged  by  the  union  of  the  veins  of  the  arms — when  the 
whole  are  concentrated  in  one  tube,  — that  last  one,  is  the  descend- 
in'* vena  cava,  — emptying  all  the  blood  from  the  head,  and  brain, 
and  arms,  into  the  auricle  of  the  right  heart.  The  jugular  veins, 
therefore,  are  the  great  veins  of  the  brain,  and  commence  behind  the 
forehead  bone,  just  between  the  eyes,  within  the  skull. 

At  the  last  joint  of  the  spine,  the  lumbar  region,  we  left 
the  descending  artery,  divided  into  two  branches.  In  as- 
cending from  the  heart,  the  large  artery  is  called  the  as-, 
cending  aorta,  and  having  made  the  curve,  the  descend- 
ing tube  is  tlic  descending  aorta. 

These  two  trunks,  now  lying  just  within  the  brim  of  the 
pelvis,  divide  again,  sending  a supply  of  blood  to  the 
muscles  and  apparatus  within  the  pelvis.  The  first  trunks 
are  the  external  iliacs,  and  the  second  set  are  internal 
iliacs.  Further  down,  in  the  thigh,  in  each  limb,  the 
arteries  appear  under  the  name  of  femoral  arteries  : — in 
the  ham,  behind  the  knee  joint,  the  poplitceal;  still  fur- 
ther, by  the  side  of  the  shin  bone,  the  tibial ; in  the  foot, 
the  planter,  and  so  on,  till  the  divisions  become  too  minute 
to  be  discernible  to  the  naked  eye. 

Between  the  arch  and  the  pelvis,  various  little  twigs 
are  thrown  off  laterally  to  nourish  the  lungs,  diaphragm, 


140 


ANATOMICAL  CLASS  BOOK. 


liver,  stomach,  spleen,  and  other  abdominal  viscera,  — 
each  bearing  a name  indicating  its  destination,  or  office, 
or  supposed  resemblance  to  familiar  objects.  Here,  then, 
we  have  exhibited  a scheme  of  the  arterial  system,  per- 
haps quite  as  well  as  to  have  accompanied  the  text  with 
many  more  drawings. 

The  arteries  must  be  nourished  themselves,  by  a free 
circulation  of  blood  in  their  coats,  as  much  as  the  heart; 
otherwise,  were  they  independent  of  the  rest  of  the  living 
body,  they  would  be  extraneous,  and  could  not  contribute 
to  its  wants.  On  the  sides  of  all  the  arteries,  millions  of 
vessels,  infinitely  fine,  more  nearly  like  tho  down  on  a 
peach  than  arteries,  conduct  a circulation.  This  tissue  or 
net  work  of  miniature  arteries,  is  the  vasa  vasorum. 
Finally,  the  arteries  are  made  up  of  several  coats,  as  though 
one  tube  were  thrust  into  another,  — which  are  muscu- 
lar and  membraneous,  according  to  their  importance. 

As  they  recede  from  the  heart,  the  tendency  is  to  keep 
subdividing,  to  supply  every  possible  part,  — hence,  ulti- 
mately, they  become  too  small  to  be  seen.  Between  these 
points,  and  the  commencement  of  the  veins,  is  ah  inter- 
mediate set  of  real  or  imaginary  vessels,  the  capillaries, 
through  which  the  blood  must  pass  to  reach  the  veins. 
Such  is  the  monstrous  size  of  the  aorta  in  a whale,  that 
the  whizzing  velocity  of  the  blood,  at  each  systole,  is 
audible  to  the  harpooners : with  the  stethoscope,  quite  a 
modern  invention,  the  rush  of  the  blood  may  be  heard  in 
our  own  species. 


ANATOMICAL  CLASS  BOOK. 


141 


Explanation  of  Fig.  61. 

It  is  utterly  impossible  as 
well  as  unprofitable,  in  an  el- 
ementary work  of  this  kind, 
intended  for  youth,  to  picture 
every  vessel  ; hut  we  were 
desirous  of  displaying  the  ar- 
teries of  the  arm  and  palm  of 
the  hand,  on  account  of  the 
beauty  and  great  importance 
of  the  structure.  What  is 
seen  in  this  drawing,  exists  in 
every  living  arm.  Over  the 
bend  of  the  elbow,  a mere 
web  lies  between  the  great 
artery  and  vein.  The  vein  is 
taken  away,  but  it  will  show 
how  dangerous  it  is  to  bleed 
the  vein,  at  this  point,  on  ac- 
count of  the  nearness  of  the 
artery,  which  is  liable  to  be 
wounded  by  the  point  of  the 
lancet.  A knowledge  of  this 
fact,  should  deter  every  one 
from  employing  surgeons  in 
whom  they  have  not  the  most 
implicit  confidence,  that  they 
understand  anatomy,  a,  b , c, 
d,  e,  f g,  h,  k,  mark  the 
branches  of  the  brachial  artery 
a,  as  they  are,  in  relation  to 
the  muscles  ; i is  the  fassia  or 
the  membrane,  between  the 
artery  and  vein,  and  which  is 
a tendinous  strip  sent  off  from 
the  biceps  flexor  cubiti  or 
bending  muscle  of  the  fore 
arm,  as  though  it  was  express- 
ly designed  to  confine  the 
throbbing  artery  in  its  place, 
and  protect  it  from  the  injuries 
to  which  it  seems  liable  by 
carrying  burdens  in  the  arms. 
This  strip  of  tendon  is  like  the 
arch  of  a bridge,  — for  if  the 
arm  is  bent,  it  is  still  tense, 
and  therefore  always  a de- 
fence. 

This  brachial  artery,  near 
the  elbow,  divides  into  branch- 


142 


ANATOMICAL  CLASS  BOOK.; 


es;  — one  of  them  sinks  into  the  muscles,  to  supply  them,  by  the 
side  of  the  ulna,  on  a line  with  the  little  finger,  and  hence  called  the 
ulnar  artery.  The  main  trunk  of  the  brachial , however,  travels 
downward,  quite  superficially,  near  the  edge  of  the  radius,  and 
therefore  has  the  name  of  radial  artery.  In  the  wrist,  being  just 
under  the  skin,  it  is  pressed  against  the  bone,  where  its  pulsations 
are  felt : — feeling  the  pulse,  in  the  language  of  physicians,  simply 
means  the  sensation  conveyed  by  the  throbbings  of  this  artery,  when 
thus  compressed.  Further  on  in  the  palm  of  the  hand,  it  forms  half 
a circle,  termed  the  palmer  arch,  and  from  its  outward  curve,  digital 
branches  convey  the  blood  to  the  fingers  and  thumb. 

That  the  arteries  possess  the  property  of  contracting 
upon  the  blood  cannot  be  denied.  The  heart,  were  it  in- 
tended to  force  the  column,  independently  of  any  assis- 
tance from  the  arteries,  through  their  whole  extent,  we 
should  suppose,  was  not  adequate  to  the  undertaking,  be- 
cause the  proportions  are  unequal,  in  comparing  the  engine 
with  the  distance  to  which  it  is  required  to  send  the  blood. 
The  pulsations  of  the  arteries,  indicate  that  they  continue 
and  propagate  the  action  which  was  commenced  by  the 
heart. 

Were  it  not  so,  of  what  Use  are  the  valves  at  the  mouth 
of  the  aorta  and  in  the  pulmonary  artery  ? If  the  volume 
to  which  an  onward  impetus  had  been  given,  could  pur- 
sue the  tortuous  windings,  quite  to  the  capillaries,  of  what 
need  were  the  valves  1 The  truth  appears  fo  be  this,  viz., 
the  ventricle  only  throws  the  blood  beyond  the  valves, 
which  are  thrust  across  the  canal  to  prevent  a regurgita- 
tion, and  then  the  artery  compresses  it  in  turn.  Onward 
it  moves,  to  some  other  place,  where,  before  the  velocity 
that  has  been  given  it  is  lost,  a second,  third  and  fourth 
pulsation,  as  the  case  may  be,  conpletes  the  circle  of  ac- 
tion. Do  we  not  actually  feel  that  the  artery  pulsates  in 
the  wrist ; and  do  we  not  also  recollect  that  in  the  fish,  an 
artery,  the  aorta,  assumes  the  office  of  a heart ; in  the 
vermin  too,  did  we  not  show  that  the  aorta  and  accompa- 
nying arteries  carried  on  the  perfect  circulation,  without 
any  heart  at  all  ? 


ANATOMICAL  CLASS  BOOK. 


143 


The  arteries  are  not  passive  tubes,  imbedded  in  the 
concealed  interstices  of  the  muscles  to  conduct  a fluid  in 
which  they  have  no  part  nor  interest.  They  are  not  qui- 
escent, like  the  wooden  pump  logs  of  an  aqueduct  corpo- 
ration, remaining  at  rest,  till  something  disturbs  them  : — 
no  ; they  are  portions  of  a living  whole,  endowed  with  a 
vitality  which  results  from  this  peculiar  combination  of  or- 
ganized matter.  They  feel  the  vigor,  or  the  decay  of  other 
parts  ; they  become  diseased  by  over  excitement ; sicken, 
refuse  to  pursue  their  accustomed  service ; and  when  the 
crazy,  shattered  frame  of  the  old  man  begins  to  tottle,  the 
arteries,  too,  begin  to  flag,  and  finally  cease  to  act  at  all. 
In  old  age  they  ossify — becoming  perfectly  bony  tubes, 
for  many  inches  together  : by  over  action,  they  are  en- 
larged into  irregular  sacks,  or  aneurisms  ; and  in  ad- 
vanced cases,  they  burst,  and  the  heart’s  blood  is  wasted 
so  quickly,  that  life  may  be  said  to  have  exploded. 

The  tendency  of  age,  is  to  relax  the  muscular  fibre,  and 
in  this  general  debility,  the  arterial  coats  suffer  — their 
diameters  enlarge,  and  their  power  is  diminished  as  their 
transverse  diameter  increases.  The  energy  of  the  pulse 
is  lost;  the  arteries,  however,  make  an  effort  to  sustain 
their  accustomed  vigor,  by  assuming  a more  tortuous 
course,  — showing,  that  the  short  curves  which  are  made 
under  these  circumstances,  are  favorable  to  the  accumula- 
tion of  physical  power. 

VEINS. 

It  is  much  easier  to  account  for  the  propulsion  of  the 
blood  from  the  heart,  through  the  arteries,  than  to  explain 
the  process  of  its  return  through  the  veins.  Their  origin 
is  in  the  capillaries,  quite  at  the  extreme  terminations  of 
the  arteries,  growing  larger  as  they  advance  towards  the 
centre  of  the  body.  They  are  seen  through  the  skin  at 
the  ends  of  the  fingers,  on  the  arms,  and  indeed  every- 


144 


ANATOMICAL  CLASS  BOOK. 


Fig.  63. 


Explanation  of  Fig.  62. 

The  anatomy  of  the  veins  being 
much  less  intricate  than  the  arteries, 
to  understand,  it  has  not  been  thought 
necessary  to  present  more  than  one 
plan  of  some  of  the  most  superficial 
vessels  of  this  order. 

On  the  calf  of  the  leg,  there  are 
g numerous  veins,  just  under  the  skin, 
uniting  into  fewer  and  fewer  branches, 
as  they  rise  upon  the  limb,  till  they 
finally  unite  in  two  principal  trunks, 
one  deep  seated,  and  the  other  super- 
ficial, which  pass  into  the  pelvis,  at 
the  gi'oin,  and  thus  convey  the  blood  to 
the  ascending  vena  cava , the  great 
vein  that  carries  all  the  blood  to  the 
heart,  which  has  been  collected  below 
it.  By  turning  to  the  drawing  of  the 
double  heart,  Fig.  2,  that  great  vein 
will  be  seen. 

d.  The  gastrocnemius. 

e.  The  nervus  saphaer.us  minor. 

f The  branch  arising  from  the  pop- 
liteal. 

g.  The  nervus  communicans,  aris- 
ing from  the  fibular  nerve. 

h.  The  popliteal  nerve. 

i.  Tlie  fibular  nerve. 

k.  The  popliteal  vein. 

/.  The  vena  saphaena  minor. 

m.  The  popliteal  artery. 

n.  n.  The  arterise,  distributed  upon 
the  calf  of  the  leg. 

p,  p.  The  muscles  on  the  back  of  the 
thigh. 

d.  The  gastrocnemius. 


where,  creeping  upward,  becoming  increased  in  size  at 
every  step,  till  they  eventually  are  reduced  in  number  to 
two  principal  trunks,  the  superior  and  inferior  cavas,  at 
the  right  auricle.  Their  coats,  which  are  the  same  as  the 
arteries,  are  thinner  and  weaker  — more  dilatable,  and 
consequently  much  oftener  diseased  and  liable  to  acci- 


ANATOMICAL  CLASS  BOOK. 


145 


dents.  Through  their  whole  track,  with  a few  excep- 
tions, there  is  a line  of  valves,  the  office  of  which  is  to 
hold  the  column  from  falling  back,  that  has  once  passed 
above  the  lock.  So  frequent  are  these  valves,  that  they 
may  be  detected  every  inch,  in  the  great  veins  of  the  arms. 
By  compressing  the  vessel  above  one  of  them,  the  blood 
at  once  accumulates  in  the  form  of  a knot,  — showing  ac- 
curately the  exact  place  of  its  locality.  The  principle  of 
fixing  a ligature  round  a limb,  as  a preparatory  step  to 
bleeding,  with  a lancet,  is  to  stop  the  blood  in  its  course,  — 
there  being  no  possibility  of  its  going  backward,  as  it  is 
held  by  the  valve, — therefore,  as  the  canal  is  closed  by 
compression  above,  the  escape  is  at  the  incision. 

We  will  not  pretend  to  inform  our  readers  how  the  blood 
travels  up  the  veins,  — lying,  as  they  do,  perfectly  quies- 
cent. It  seems  as  though  there  must  he  a propulsive  force 
exerted  somewhere  in  the  vicinity  of  the  capillaries,  to 
thrust  the  blood  along,  yet  dissection  gives  us  no  clue  to 
the  mystery. 

The  veins  also  perform  other  interesting  duties,  acting 
as  absorbents,  accompanying  the  arteries,  wherever  they 
may  go,  to  be  servants  in  waiting,  — to  pick  up,  and  carry 
home  whatever  may  have  been  conveyed  to  a distance  by 
their  superiors. 

CIRCULATION  OF  TIIF.  BLOOD. 

Were  it  not  necessary  in  the  plan  of  animal  life  to  pre- 
sent every  particle  of  blood,  at  certain  intervals,  to  the 
influence  of  atmospheric  air,  there  would  have  been  no 
need  of  a heart.  We  might  have  been  born  with  a suffi- 
cient quantity  in  our  bodies,  where  it  might  have  remained 
undisturbed,  fulfilling  the  intentions  of  its  design.  Such 
a state  of  things,  however,  is  not  admissible,  because  it  is 
secreted  into  the  vessels  to  increase  the  growth,  to  repair 
13 


146 


ANATOMICAL  CLASS  ROOK, 


the  wastes,  and  to  sustain  the  whole  by  its  vivifying  pres» 
ence.  Every  bone,  muscle,  tendon,  nerve,  membrane  and 
fluid,  is  made  out  of  the  blood.  As  the  parts  to  be  made 
cannot  fabricate  themselves,  and  afterwards  take  their  ap- 
pointed  stations,  the  blood  goes  to  the  spot  where  this  is  to 
be  effected,  leaving  material  for  a bone  in  one  place,  glue 
to  hold  particles  together  in  another,  and  so  on,  in  its  ac- 
tive round.  But,  on  the  other  hand,  these  particles  can- 
not fashion  themselves ; — the  point  of  an  artery,  there- 
fore, at  which  they  are  given  off,  assumes  the  office  of  an 
artisan,  and  moulds  and  finishes  the  work. 

We  here  discover  that  the  arteries  possess  a wonderful 
property,  which  was  not  spoken  of  in  the  preceding  para- 
graphs. Industrious  and  unerring  in  all  the  first  years 
of  life,  invariably  conveying  just  the  soit  of  material  that 
may  be  wanted  to  mend  a broken  bone,  to  heal  a cut  finger, 
or  to  lubricate  a joint,  they  grow  careless  in  forty  years  : — 
they  neglect  supplying  the  eyes  with  sufficient  quantities 
of  humors  to  distend  the  ball,  so  we  meet  the  emergency 
by  wearing  spectacles:  they  are  forgetful  of  the  order  by 
which  their  early  labors  were  regulated,  — and  as  one 
mistake  leads  to  the  commission  of  another ; lime  is  car- 
ried to  the  heart,  where  the  valves  become  bony  , the 
urinary  apparatus  is  carelessly  watched,  and  stones  form 
in  the  bladder ; the  teeth  are  not  supplied  with  earthy 
matter  in  season  to  prevent  their  decay  : — the  hair  is  not 
watered  at  the  roots,  and  it  becomes  dry  and  falls  off. 

Such  cursory  remarks  as  these,  exhibit  a bird’s-eye  view 
of  the  importance  and  multifarious  functions  of  the  arte- 
ries, and  demonstrates  the  high  value  of  the  blood,  from 
which  so  much  and  such  inimitable  machinery  is  formed. 

As  we  now  comprehend  the  use  of  the  circulation,  we 
will  next  endeavor  to  solve  another  apparently  difficult 
problem  — the  why  it  is  necessary  to  throw  the  blood  into 
the  air  cells  of  the  lungs. 


ANATOMICAL  CLASS  BOOK. 


J47 


fSig.  63. 


Explanation  of  Fig.  6;?. 

If  the  student  is  desirous  of  thoroughly  and  clearly  understanding 
the  circulation  of  the  blood,  as  it  moves  in  his  own  body,  let  him 
stow  recapitulate  the  subject,  by  following  the  venous  or  black  blood 
from  the  two  great  supplying  vein's,  till  it  arrives  in  the  main  dis- 
tributing artery,  purified,  re-vitalized  and  in  a condition  to  sustain 
animal  life. 

the  descending  vena  cava,  returning  black  blood  from  the  head 
and  upper  extremities. 

n,  the  ascending  vena  cava,  returning  the  same  kind  of  blood  from 
the  lower  parts  of  the  body. 

ti,  the  right  auricle  of  the  heart,  where  both  veins  meet. 

; p , and  x,  veins  from  the  liver,  spleen  and  bowels,  uniting  with  the 
inferior  cava. 

The  auricle  being  filled,  contracts  and  forces  the  blood  into  b,  the 
ventricle:  next  the  ventricle  contracts  and  sends  it  into  k,  the  pul- 
monary artery,  which  branches  into  1 , 1 , to  supply  the  lungs  in  both 
sides  of  the  chest  From'the  lungs,  where  a scarlet  color  has  been 
given  it,  four  veins  of  the  lungs  gather  it  together,  and  deposit  it  in 
the  left  auricle  r-  that  contracts,  and  the  blood  is  driven  into  the 
left  ventricle  a;  lastly,  the  ventricle  contracts  and  throws  it  into  c, 


14S 


ANATOMICAL  CLASS  COOK. 


(lie  aorta,  which  conducts  it  over  and  through  every  bone,  muscle 
and  organ. 

Under  a solar  microscope,  the  circulation  of  the  blood  in  the  thin 
web  of  a frog’s  foot,  and  several  other  reptiles,  may  be  distinctly  ob- 
served; and  in  insects,  while  they  remain  worms,  the  pulsations  of 
(he  artery  which  acts  instead  of  a heart,  are  readily  perceived.  In 
the  oyster,  the  heart  pulsates  about  thirty-seven  times  in  a minute. 

Before  birth,  the  blood,  instead  of  going  from  the  auricle  of  the 
right  heart  down  into  the  ventricle,  to  be  thrown  into  the  lungs, 
passes  directly  through  a valve  in  the  partition  wall  between  the  two 
auricles,  and  thus  gets  into  the  left  side,  or  left  heart.  The  reason 
why  the  blood  is  not  sent  to  the  lungs,  is  because  they  have  not  yet 
assumed  the  function  of  breathing.  At  biith,  when  the  first  breath 
of  air  is  inhaled  that  ever  entered  the  lungs,  the  valve  closes  up  the 
opening  forever,  and  the  blood  then  takes  a circuitous  route  through 
the  lungs,  for  the  reason  which  has  been  already  so  familiarly  ex- 
plained. 

The  sign  of  the  vitality  of  the  blood  is  its  scarlet  colon 
which  it  only  exhibits  in  the  heart  and  arteries.  When  it 
goes  from  the  heart,  it  is  charged  with  the  presence,  or 
admixture,  of  every  material  which  can  possibly  be  re- 
quired; but  ou  its  way  to  the  capillaries,  all  these  several 
materials,  supposed  to  be  in  solution,  are  dropped  on  the 
way,  so  that  when  the  refuse,  that  is,  the  fluid,  which  was 
merely  the  medium  of  conveyance,  enters  the  extreme  be- 
ginnings of  the  veins,  its  color  is  almost  black. 

Having,  therefore,  imparted  all  its  needful  qualities,  it  is 
totally  unfit  to  be  sent  round  a second  time,  till  it  is  re- 
charged. To  obtain  this  quality,  now  lost,  the  right  heart 
sends  it  into  the  lungs.  Surrounding  each  distended  air 
cell,  is  a thin  sheet  of  black  venous  blood,  which  by  the 
mysterious  influence  of  the  contained  air,  changes  the 
color,  instanter,  to  its  original  scarlet.  The  orgasm,  the 
suddenness  of  the  change,  cannot  be  conceived — yet 
the  whole  mass  is  re-vitalized,  and  is  now  carried  into  the 
left  heart,  to  be  again  sent  over  the  old  ground.  Such,  in 
familiar  language,  is  the  circulation  of  the  blood  — a pro- 
cess well  calculated  to  raise  our  admiration  for  the  charac- 
ter and  transcendent  power,  and  condescending  goodness 
of  our  Creator. 


ANATOMICAL  CLASS  BOOK. 


149 


Anatomists  in  treating  of  this  important  fluid,  speak  of 
its  being  composed  of  three  substances,  viz  ; serum,  the 
watery,  yellowish  fluid  ; fibrin,  the  crassamention,  or  cake  ; 
and  the  coloring  matter.  Were  we  not  restricted  in  this 
work  to  certain  limits,  it  would  certainly  be  an  entertain- 
ing theme  to  detail  the  extravagant  whims  which  the  old 
authors  entertained  upon  the  subject  of  the  red  globules  of 
the  blood.  It  actually  seems,  to  a calm  spectator,  who 
surveys  the  past  and  compares  it  with  the  present,  as 
though  the  physiologists  of  the  two  last  centuries  bowed 
down  to  make  themselves  positively  ridiculous,  by  the 
sweat  of  the  brow.  When,  by  some  fortuitous  circum- 
stance, it  was  ascertained  that  the  florid  hue  of  the  blood 
depended  on  the  actual  pressure  of  floating  globules,  of 
different  sizes,  ye!  so  minutely  small  as  to  appear  like  the 
coloring  of  an  infusion,  they  set  to  work  in  earnest  to  in- 
vestigate their  use  and  structure.  About  the  same  time,  un- 
luckily, a philosopher  invented  the  compound  microscope, 
which  enabled  every  body  to  peep  into  microcosms,  where 
they  beheld  sights,  quite  imaginary  in  most  cases,  more 
astonishing  than  were  ever  before  revealed  to  human  eyes. 

Whether  they  saw  distinctly  or  not,  it  is  now  of  little 
consequence  ; but  at  all  events,  they  asserted  the  want  of 
uniformity  in  the  size  of  the  globules,  though  each  one 
was  a hexagon,  built  up  regularly  and  mathematically,  as 
an  architect  could  construct  a country  seat,  of  six  smaller 
hexagons  ! However  small  — and  some  where  supposed 
to  be  immensely  beyond  the  magnifying  reach  of  their 
glasses — they  were  all  framed  in  the  same  workman-like 
manner. 

All  this  fine  discovery  being  settled  and  indisputably 
admitted  — for  it  would  have  been  outrageously  impolite 
for  those  who  had  no  microscopes,  to  call  the  marvellous 
discovery  in  question  — their  wits  were  in  labor  to  devise 
a rank  for  them  in  the  circulation.  This,  too,  was  accom- 
id* 


150 


ANATOMICAL  CLASS  BOOK. 


plished ; but  to  find  out  the  diseases  that  originated  in 
consequence  of  the  mistakes,  or  refractory  conduct  of  the 
compound  balloons,  was  a poser.  There  is  nothing,  by 
the  way,  like  perseverance.  A man  who  is  lost  in  a fog, 
has  but  one  course  to  pursue,  and  that  is  to  take  care  of 
himself:  so  it  was  with  our  discoverers;  they  had  their 
mathematical  bladders  on  hand,  which  must  be  disposed 
of — and  here  they  are,  in  all  their  beauty  of  arrange- 
ment, from  the  plastic  hands  of  their  discoverers. 

Diseases  were  the  effects  arising  from  error  loci  — that 
is,  some  of  the  large  globules,  fitted  to  the  calibre  of  a par- 
ticular artery,  got  wedged  by  some  sad  mishap  at  the 
mouth  of  a smaller  vessel,  or,  becoming  angry,  refused  to 
operate  in  the  harness,  so  puffed  up  — clogged  the  pass- 
age — and  this  produced  inflammation,  out  of  the  modifi- 
cations of  which  fevers,  dropsies,  and  all  the  other  ills  that 
flesh  is  heir  to,  had  a bona  fida  origin  ! 

Enough  has  been  written  to  stimulate  our  readers  to 
the  perusal  of  the  old  records  of  physiological  folly,  in  the 
original  tongue,  if  they  wish  for  an  uninterrupted  history 
of  that  singular  discovery.  To  those  who  are  more  inter- 
ested in  the  anatomical  facts  we  have  been  relating, 
touching  the  heart  and  the  arteries,  it  is  needless  to  re- 
commend them  to  the  writings  of  those  who  are  teachers 
by  profession.  Perhaps  we  may  have  committed  ourselves 
in  the  ardor  of  the  moment,  by  advancing  ideas  quite  as 
absurd  as  those  which  we  have  been  condemning;  but  in 
the  demonstration  of  parts,  we  are  conscious  of  being  right, 
having  given  the  anatomy  of  the  circulation  as  we  have 
found  it,  by  years  of  toil ; and  as  it  regards  theories,  things 
made  at  little  expense,  like  castles  in  the  air,  we  are  not 
tenacious  about  the  respect  that  may  be  paid  to  them. 
Having  been  right  merry  over  the  conceits  of  our  profes- 
sional predecessors,  we  are  quite  willing  to  be  laughed  at 
in  turn. 


ANATOMICAL  CLASS  BOOK. 


151 


QUESTIONS. 


Had  the  ancients  a knowledge  of  the  circulation  ? 

How  did  they  explain  the  movements  of  the  blood  ? 

What  is  the  heart  ? 

Is  the  heart  a single  or  compound  organ  ? 

In  what  animals  is  the  heart  single  P 
Why  is  it  necessarily  single  in  fishes  ? 

How  does  it  act? 

How  many  cavities  has  the  heart  ? 

What  prevents  the  blood  from  rushing  into  the  wrong  apart- 
ments ? 

Has  it  a circulation  of  blood  for  its  own  service  P 
What  are  the  auricles? 

What  are  the  ventricles  ? 

What  is  the  use  of  the  valves  ? 

Has  the  heart  any  nerves  ? 

Why  has  the  will  no  control  over  it? 

Where  is  the  heart  located  ? 

Is  it  covered  by  any  membrane  ? 

Why  are  not  the  pulsations  felt  in  the  right  side  ? 

How  does  the  right  heart  differ  from  the  left? 

What  is  an  artery  ? 

Where  is  the  principal  artery  of  the  body  found  ? 

What  veins  return  all  the  blood  to  the  heart  ? 

Are  there  valves  in  the  veins  ? 

Has  the  aorta  any  valves  ? 


152 


ANATOMICAL  CLASS  COOK. 


Where  does  the  pulmonary  artery  arise  ? 

Where  are  the  carotid  arteries  ? 

By  what  arteries  is  the  brain  supplied  with  blood  ? 

Is  the  heart  a forcing  engine  ? 

How  are  the  pulses  perceived  in  the  wrist? 

What  is  the  use  of  the  pericardium  ? 

What  change  is  effected  on  the  blood  in  the  lungs  ? 
What  color  has  the  blood  in  the  veins  ? 

What  color  has  the  blood  in  the  arteries  P 
Does  blood  circulate  in  the  bones  ? 

By  what  organs  are  all  parts  of  the  body  fashioned  ? 

Of  what  use  is  the  blood  in  an  animal  ? 

How  is  the  blood  supplied  ? 

What  is  the  object  of  taking  food  into  the  stomach  ? 

Is  it  known  by  what  power  blood  is  moved  in  the  veins  ? 
What  is  the  composition  of  the  blood  ? 

Why  are  some  animals  denominated  cold  blooded  ? 

Is  the  blood  warm  in  reptiles  having  a single  heart  ? 

Can  any  animal  exist  long,  deprived  of  its  heart  ? 

What  is  understood  by  the  irritability  of  the  heart? 


ANATOMICAL  CLASS  BOOK. 


153 


THE  NERVES, 


OR  NEUROLOGY. 


Neurology  teaches  us  the  anatomy  and  physiology  ot 
the  nerves. 

The  brain  is  the  radiating  point  whence  the  nerves, 
to  a considerable  extent,  have  their  origin.  The  spinal 
marrow,  from  which  an  immense  number  of  nerves  branch 
out,  is  considered  in  reality  by  some,  a prolongation  of 
the  brain  itself.  Phrenologists,  on  the  other  hand,  sup- 
pose the  brain  arises  from  the  spinal  marrow,  because  the 
brain  is  sometimes  wanting,  but  the  nerves  are  always 
present. 

In  the  first  place,  the  contents  of  the  head  are  divided 
into  the  cerebrum  and  cerebellum,  or  in  other  words,  the 
great  and  small  brains.  Above  the  level  of  the  ears,  all 
the  upper  portion  of  the  skull  is  occupied  by  the  cerebrum, 
wnich  is  the  immediate  seat  of  intellect.  Below  that  level, 
in  the  lower  and  back  part  of  the  head,  is  the  cerebellum 


154 


ANATOMICAL  CLASS  BOOK. 


Fig.  64 


Explanation  of  Fig.  64. 


This  is  an  exhibilion  of  a vertical  section  of  the  bones  of  the  head, 
fare  and  brain,  showing  precisely  the  appearance,  were  the  head  di- 
vided in  the  middle,  from  the  top,  down  to  the  neck.  No  letters  of 
leference  have  been  inlroduced,  because  the  plate  will  be  doubly 
valuable,  when  the  general  relation  of  the  different  portions  have 
been  learned  from  the  text  and  the  other  diagrams.  The  reader  will 
then  trace  with  his  eye  the  outline  of  the  little  brain,  the  cerebrum, 
or  large  brain,  the  seat  of  thought ; the  ventricles  and  other  interest- 
ing points,  which,  though  intricate,  are  nevertheless  worth  the  trou- 
ble of  understanding.  The  mechanical  arrangement  is  only  contem- 
plated in  these  illustrations:  — the  functions  of  the  brain  in  a treatise, 
purely  elementary,  would  be  wholly  useless. 

or  little  brain.  They  are  separated  from  each  other  by  a 
membrane,  tensely  stretched.  Otherwise,  the  weight  of 
the  upper  mass  would  oppress  t he  functions  of  the  lower 
one.  By  a vertical  line,  the  brain  is  divided  into  hemi- 
spheres, as  right  and  left ; but  when  it  is  dislodged  from  the 
head,  and  inverted,  the  underside  presents  three  promi- 
nent risings,  which  are  denominated  lubes.  Those  por- 
tions of  the  brain  directly  behind  each  eye,  are  the  ante- 
rior lobes.  Those  at  the  back  side  of  the  head,  the  poste- 
rior; and  the  third,  between  them  both,  are  the  middle 
lobes. 


anatomical  class  book. 


155 


COATS  OF  THE  I!  It  A I N AND  NERVES. 

In  this  plain  exposition  of  the  anatomy  of  the  nervous 
system,  ii  would  be  an  endless  labor  to  attempt  a minute 
detail  of  the  three  different  coverings,  which  surround  the 
intellectual  apparatus,  independently  of  the  bony  box,  the 
strong  wall  that  envelops  the  whole. 

firm  coat,  or  — Dura  Mater . 

When  the  skull  is  opened,  a dense,  shining  membrane 
is  presented,  that  keeps  the  brain  together,  when  the 
bones  are  taken  entirely  away.  Completely  embracing 
the  entire  organ,  it  becomes  thicker  round  the  medulla 
ob/onga,  to  defend  this  narrowing  of  the  brain,  over  the 
bones  of  the  neck,  — then  continues  its  course  through 
the  whole  length  of  the  back-bone,  embracing  the  mar- 
row' : wherever  a branch  or  side  nerve  is  given  off,  a por- 
tion of  the  dura  mater  follows  it,  precisely  as  the  bark  of 
the  trunk  covers  the  branching  limbs.  In  the  still  smaller 
divisions  of  the  nerve,  a continuous  tube  of  the  dura  mater 
is  found,  till  both  are  finally  lost  on  the  exterior  surface. 
This  membrane,  let  it  be  remembered,  holds  the  office  of 
defending  the  pulp  of  the  nervous  matter  within  its  em- 
brace, wherever  the  nerves  may  traverse. 

transparent  coat,  or — Tunica  Araclmoides. 

Perhaps  there  is  not  a more  delicate,  transparent  mem- 
brane in  the  whole  body  than  this,  — so  much  resembling 
a spider’s  web,  that  from  this  circumstance  it  has  its  name. 
This  lies  over  the  convolutions  of  the  brain,  directly  under 
the  dura  mater,  and  does  not  dip  down  between  the  pro- 
minences. Beside  surrounding  the  brain,  like  the  other, 
it  has  precisely  the  same  infinite  distribution  — making 
the  second  tube  for  defending  the  nerve. 


156 


: ANATOMICAL  CLASS  BOOK. 


soft  coat,  or  — Pia  Malcr. 

Blood  must  be  everywhere  freely  circulated ; but  in  the 
brain,  it  is  necessarily  thrown  into  that  portion  which  is 
the  seat  of  thought,  in  very  minute,  hair-like  currents,  — 
otherwise  the  force  of  the  heart,  which  acts  upon  the 
principle  of  a forcing-pump  or  syringe,  would  tear  it  to 
pieces.  This  pia  mater,  therefore,  is  an  immense,  broad, 
thin  net  of  blood-vessels,  following  the  fissures  and  wind- 
ing into  the  very  centre  of  the  brain,  and  also  pursues  the 
nerves,  wherever  they  may  go,  always  in  attendance  to 
furnish  the  vital  fluid,  on  which  health,  sensibility,  and, 
indeed,  all  the  vital  functions  are  forever  depending. 

STRUCTURE  OF  THE  BRAIN. 

The  centre  of  the  nervous  system  is  the  brain,  within 
the  bones  of  the  head,  with  the  exception  of  that  class 
of  animals,  which,  as  it  were,  are  the  uniting  links  be- 
tween the  vegetable  and  animal  kingdom;  — the  worms 
are  without  it : fishes  too,  and  amphibious  reptiles  have 
scarcely  a development  of  the  nervous  mass,  entitling  it 
to  the  appellation  of  brain.  We  suppose,  however,  that 
we  are  contemplating  the  human  brain,  a singular,  but 
splendidly  constructed  piece  of  mechanism,  made  up  of 
an  infinite  congeries  of  delicate  cords, — and  equally  at- 
tenuated blood  vessels. 

It  was  once  thought  that  we  had  but  one  brain,  but 
modern  discovery  assures  us  that  we  possess  four  ! and  that 
two  of  them  mutually  cooperate,  in  function,  with  the 
others. 

There  is  no  particular  point  where  the  brain  can  be 
said  to  begin,  nor  a point,  in  fact,  where  it  terminates.  Let 
the  reader  suppose  that  on  the  first  joint  of  the  neck,  just 
under  the  head,  two  large  cords  are  lying,  side  by  side  : 
entering  the  great  natural  opening  of  the  skull,  they  are 


ANATOMICAL  CLASS  BOOK. 


157 


subdivided  into  millions  of  threads,  — portions  of  which 
assume  different  forms,  to  which  anatomists  give  specific 
names,  — as  cruri,  pons,  &c.  But  as  the  threads  are 
merely  subdivisions  of  the  one  cord,  — the  mystery  is,  at 
first  view,  how  comes  such  an  increased  quantity  '?  noth- 
is  more  simple  than  an  explanation.  Admitting  the  fibres 
to  be  indefinitely  long, — the  folding  and  refolding  of  one 
upon  another,  in  conjunction  with  an  artery  and  vein  — 
there  is  no  difficulty  in  giving  an  answer.  For  the  evi- 
dence of  a fibrous  structure,  this  infinite  volume  of  threads, 
we  refer  to  the  positive  demonstration  of  the  brain  by  the 
late  Dr  Spurzheim. 

Most  of  the  organs  are  double,  and  it  was  highly  neces- 
sary that  the  brain  should  be  so  also.  The  great  brain 
cerebrum,  in  the  upper  part  of  the  head  and  over  the  eyes, 
is  the  immediate  seat  of  intellect,  and  in  halves;  in 
other  words,  there  is  one  on  each  side,  divided,  above 
from  each  other,  in  the  middle,  by  a membrane.  Under 
this,  in  the  lower  and  back  part  of  the  head,  is  the  cere- 
bellum, or  little  brain,  belonging  to  the  animal  system, 
and  totally  different  in  function  from  the  other;  this  too, 
is  in  two  pieces. 

Below  the  point  on  the  neck  bone  on  which  the  two 
lateral  cords,  termed  medulla  oblonga,  lie,  extending  with- 
in the  bones,  the  whole  length  of  the  spine  or  back-bone, 
the  same  cords  are  seen  — giving  out,  between  the  points, 
ribs,  &c,  branches,  — called  spinal  nerves.  Those  within 
the  chest  take  the  name  of  thoracic  nerves;  — still  lower, 
between  the  ribs,  intercostal , and  still  further  down,  be- 
tween the  bones  of  the  back,  the  lumbar  nerves.  The 
•limbs  of  a tree,  shooting  out  from  the  trunk,  precisely  rep- 
resent this  part  of  the  anatomy  of  the  spinal  marrow. 

Let  it  be  remembered,  that,  from  the  head  to  the  termi- 
nation of  the  spinal  marrow,  two  cords,  two  brains,  two 
little  brains,  and  two  distinct  sets  of  lateral  nerves  exist 
14 


158 


ANATOMICAL  CLASS  BOOK 


lying,  however,  in  juxtaposition,  intimately  united  by  the 
decussation  of  fibres,  which  run  from  one  to  the  other. 

This  cerebral  substance  is  so  soft,  that  without  its  en- 
veloping membranes,  it  would  fall  to  pieces,  by  its  own 
weight.  These  membranes  possess  but  a very  slight  de- 
gree of  sensibility  ; — being  of  a mealy  whiteness,  and  in 
the  skull  possessing  but  little  elasticity,  though  in  the  body 
and  limbs,  this  quality  necessarily  exists,  or  they  would 
become  elongated  and  flaccid  in  the  constant  flexions  of 
the  extremities. 

Whilst  this  nervous  matter  preserves  its  vitality,  it  pre- 
serves a slight  degree  of  cohesion,  but  after  death,  it 
speedily  begins  to  decay,  and  ultimately  melts  down  into 
an  oily  fluid.  As  before  remarked,  the  composition  of  the 
pulp  of  the  nerves  and  the  brain,  are  precisely  the  same, 
in  appearance,  in  life,  and  chemical  analysis  conclusively 
presents  the  same  elements  after  death. 

When  wounded,  even  badly,  the  brain  feels  no  pain,  al- 
though the  very  centre  of  sensation.  It  is  not  uncommon 
for  portions  of  the  brain  to  escape  through  fractures  of  the 
skull,  and  yet  the  person  perfectly  recover,  and  never  suf- 
fer, in  any  quality  of  his  mind,  from  the  loss  of  this  impor- 
tant corporal  substance. 

Let  it  here  be  recollected  that  all  the  nerves  which  go 
from  the  head  or  spinal  marrow,  however  much  they  may 
be  distributed  within  the  muscles,  invariably  run  towards 
the  surface  of  the  body  ; they  do  not,  however,  end  in  blunt 
extremities  under  the  skin,  like  the  cut  end  of  a twine;  — 
on  the  contrary,  they  are  so  infinitely  subdivided,  that  the 
single  cord  which  we  find  between  two  points  of  the  spine 
may  finally  become  a perfect  brush,  in  the  course  of  dis- 
tribution, and  lost  in  the  masses  of  flesh  through  which 
it  travels,  till  it  can  no  longer  be  recognised  by  the 
naked  eye. 


ANATOMICAL,  CLASS  BOOK 


159 


Explanation  of  Fig.  65. 

S,  the  annular  ligament  which  binds  down  the  muscles  and  vessels 
to  the  ankle  bone,  to  keep  them  in  place-  i?,  the  extensor  brevis 
digitorum,  which  assists  in  extending  the  toes.  Fig.  1,  superficial 
threads  of  the  deepseated  nerves  of  the  leg  and  instep,  emerging  upon 
the  top,  and  losing  themselves  in  the  skin.  Fig.  2,  are  long,  but 
superficial  cutaneous  branches  of  the  tibial  nerve,  sent  into  the  skin 
and  cellular  membrane  at  the  root  of  the  toes  and  ball  of  the  great 
toe.  The  trunk,  from  which  these  twigs  have  their  origin,  originated 
within  the  pelvis,  yet,  notwithstanding  they  were  concealed,  deep 
in  the  flesh,  the  whole  length  of  the  limb,  they  finally  make  their 
appearance  at  the  surface.  This  figure,  therefore,  is  designed  to  il- 
lustrate the  position  maintained  in  the  text,  viz,  that  all  the  nerves 
have  a direction  towards  the  external  surface  of  the  body. 

THE  MECHANISM  OF  THE  NERVES. 

As  the  brain,  all  experience  proves,  is  the  seat  of  intel- 
lect, so  also,  incontestible  evidence  teaches  us  that  the 
nerves  are  parts  which  are  susceptible  of  painful  or  pleas- 


Fig.  65. 


/ 


1(30 


ANATOMICAL  CLASS  BOOK. 


urable  sensations.  Thus  a piece  of  sugar  is  grateful  to 
the  gustitory  or  tasting  nerves  of  the  tongue  ; — but  to- 
bacco, before  accustomed  to  its  nauseating  character,  has 
a directly  opposite  effect.  Pressure  on  the  sciatic  or  great 
nerve  of  the  leg,  by  sitting  too  long  in  one  position,  pro- 
duces the  disagreeable  feeling,  commonly  called  sleep  in 
the  foot ; if,  however,  the  attitude  is  not  changed,  to  re- 
lieve the  pressure,  a partial  palsy  of  the  limb  must  ensue. 

Difficult  as  it  is  to  ascertain  precisely,  the  structure  of 
the  inner  substance  of  the  nerves,  it  is  reasonable  to  infer, 
from  analogy,  as  the  substance  is  so  exactly  like  that  of 
the  brain,  that  they  are  constituted  of  a multitude  of  mi- 
nute, soft,  pulpy  parallel  cords.  Instead  of  saying  that  the 
nerves  have  their  origin  in  the  brain  or  spinal  marrow, 
they  should  be  called  the  prolongations  of  the  brain.  Their 
internal  substance,  both  physically  and  chemically  con- 
sidered, presents  the  same  results.  They  are  the  tenta- 
cula3  of  the  brain, — analogous  to  the  feelers  of  insects, 
by  which  it  takes  cognizance  of  external  things:  — the 
instruments  of  the  will,  and  the  ever  faithful  sentinels  at 
the  outposts,  giving  the  earliest  and  most  certain  intel- 
ligence of  whatever  is  of  consequence  to  the  safety  and 
well  being  of  the  individual. 

If  they  possess  an  organization  like  the  brain,  or  in  fact, 
are  simply  a prolongation  of  it,  into  the  extremities  of  the 
limbs,  the  question  may  be  asked  why  they  are  not  con- 
scious, in  their  individual  capacity  — and  why  it  is  neces- 
sary to  make  reference  to  the  superior  mass  of  the  same 
material,  within  the  skull  ? 

In  the  very  lowest  orders  of  animals,  such  is  the  case,  to 
a certain  extent:  the  worms  are  without  brain,  yet  they 
pursue  unvarying  instinctive  actions,  and  avoid  enemies 
or  caress  friends,  with  as  much  certainty  as  those  pos- 
sessing a well  marked  one. 

Nothing  can  be  more  perplexing,  than  the  nerves,  being 


ANATOMICAL  CLASS  BOOK. 


JG! 


of  all  sizes,  from  a quarter  of  an  inch  in  diameter,  to  hair- 
like threads,  invisible  to  the  naked  eye. 

Certain  it  is,  that  this  apparent  confusion  presents  the 
same  appearance  in  all  animals  of  the  same  species  : 


Fig.  66. 


14* 


162 


ANATOMICAL  CLASS  BOOK. 


Explanations  of  Fig.  66. 

MUSCLES. 

A.  Pectoral  muscle. 

B.  Detoid  muscle. 

C.  Latissimus  dorsi  muscle. 

D.  Serratus  major  anticus  muscle. 

E.  Biceps  Flexor  Brachii. 

F.  Round  tendon  of  the  biceps,  crossing  (he  elbow  joint. 

G.  The  broad  expansion  of  the  biceps,  shooting  into  the  fassia  of 
the  fore  arm. 

H.  Triceps  extensor  muscle. 

I.  Bracheus  internus  muscle,  an  auxiliary  to  the  biceps. 

K.  Coraco  Bruchialis  muscle,  an  assistant  to  the  deltuides. 

L.  Supinator  Brevis  muscle,  turns  the  palm  of  the  hand  and  fore 
arm  foi  ward. 

M.  Supinator  Inngus,  operates  in  unison  with  the  brevis. 

N.  Extensor  Radialis  Longior,  extends  the  fore  arm. 

O.  Many  flexor  muscles  of  the  fingers,  all  arising  from  one  point. 

P.  j Flexor  digitorum  profundis,  bends  the  joint  of  the  fingers. 

R.  Annular  ligament  of  the  wrist,  bending  the  tendons  in  a 
groove. 

S.  Short  muscles,  forming  the  hall  of  the  thumb. 

T.  Flexor  and  abductor  muscles  of  the  little  finger. 


N e r v e s . 


1.  1.  Radial  nerve. 

2.  2.  Ulnar  do. 

3.  External  cutaneous  nerve. 

4.  Muscular  spiral  nerve;  supplies  the  flesh  on  the  back  side  of 
the  arm  and  skin. 

5.  A communicating  twig. 

6.  Articular  nerve,  round  the  joint. 

7.  Internal  cutaneous,  supplies  the  skin  under  side  of  the  arm. 

8.  External  cutaneous,  again;  passing  through  a muscle,  and 
then  becoming  a cutaneous  nerve. 

9.  Bl  anch  of  the  external,  going  to  the  back  of  the  thumb. 

10.  Muscular  spiral  nerve. 

11.  A branch  of  the  external  cutaneous. 

12.  The  radial  nerve.  } 

, o m i > duierent  views. 

13.  I he  ulnar  nerve,  j 

14.  A branch  of  the  ulnar,  to  the  back  of  the  hand. 

15.  Distribution  of  the  radial  nerve  to  the  thumb,  fore  finger, 
middle  and  one  side  of  the  ring  finger. 

16.  Distribution  of  the  ulnar  nerve  to  the  other  side  of  the  ring, 
and  both  sides  of  the  little  finger. 

N.  B.  We  have  exhibited  in  this  plate  a mass  of  muscles  and  nerves, 
that  the  reader  may  have  some  idea  of  the  complex  machinery  ne- 
cessary to  the  perfection  of  only  one  single  limb. 


ANATOMICAL  CLASS  BOOK. 


163 


wherever  there  is  a twig  in  one  body,  leading  to  an  organ, 
precisely  such  another,  fulfilling  exactly  the  same  office, 
may  be  demonstrated  in  another  : a curious  illustration  of 
this  remark  is  strikingly  manifested  in  the  nerves  of  the 
human  hand. 

The  arteries  are  not  invariably  constant,  or  undeviating 
travellers  of  a particular  muscle.  With  the  nerves,  the 
case  is  altered  : — they  are  constant,  as  it  respects  the 
origin,  course  and  ultimate  distribution  — go  where  they 
may,  a precise  number  of  branches  are  required,  to  be  dis- 
tributed to  every  portion  and  piece  in  which  a blood  ves- 
sel enters.  Usually,  the  deep  seated  nerves  accompany 
the  arteries  ; and  the  nerves  of  the  skin  keep  in  the  track 
of  the  superficial  veins. 

Though  the  nerves  are  small,  and  uninfluenced  by  voli- 
tion, exact  order  is  preserved,  or  the  same  effects  could 
not  be  produced  in  two  individuals,  from  the  same  causes. 

Without  nerves,  there  could  be  no  sensation  : — with- 
out them,  neither  painful  or  pleasurable  emotions  would 
be  recognised ; without  them,  organized  beings  would 
be  completely  motionless,  without  locomotion,  and  with- 
out perception  or  consciousness. 

It  matters  not  how  perfectly  the  muscles  are  developed, 
or  advantageously  arranged,  if  there  were  no  mode  of  sub- 
jecting them  to  the  influence  of  the  brain,  — they  would 
be  of  no  kind  of  consequence. 

Were  the  nerves  in  the  wrist  divided,  the  ability  to 
clench  the  fingers  would  be  lost ; nor  can  it  be  recovered, 
unless  a re-union  of  the  divided  portions  can  be  effected. 
These  are  the  voluntary  nerves. 

Those  denominated  involuntary , administering  to  the 
involuntary  muscles,  are  equally  important  to  the  hidden 
regions  in  which  they  are  found.  Wrhen  the  breathing 
nerve  of  the  diaphragm  is  separated,  the  midrif  no  longer 
renders  assistance  in  respiration.  The  muscles  of  the 


164 


ANATOMICAL  CLASS  BOOK. 


chest  are  compelled  to  carry  on  the  process  of  breathing 
entirely  alone.  By  dividing  minute  twigs,  as  they  creep 
into  the  vocal  box  of  a dog,  the  muscles  are  paralyzed, 
and  the  animal  can  never  afterwards  bark. 

Digestion  in  the  stomach  may  be  interrupted  by  cutting 
the  main  trunks  of  the  nerves.  Even  the  functions  of  the 
liver  and  kidneys  might  be  checked  in  the  same  way, 
were  it  possible  to  reach  the  nerves  going  to  them,  with- 
out violence. 

Notwithstanding  the  heart  is  kept  in  continual  nuiotio 
by  the  presence  of  the  blood,  if  its  nerves  were  separa- 
ted, so  that  the  communication  were  interrupted  with  the 
brain  and  spinal  marrow,  it  would  cease  to  pulsate,  though 
its  irritability,  an  original  endowment  of  the  muscle, 
might  remain  a considerable  time.  And  still  further,  a 
wound  or  compression  of  the  spinal  marrow  completely 
paralyzes  the  whole  body, — which,  if  not  speedily  re- 
lieved, ends  in  death. 

For  the  sake  of  method,  anatomists  have  made  a regu- 
lar classification  of  the  nerves:  — 

From  the  brain,  there  are  nine  pair  — a majority  of 
which  are  the  nerves  of  sense;  — in  other  words,  they 
are  expended  on  the  organs  of  sense,  as  the  ear,  eye,  nose, 
and  tongue. 

Issuing  from  between  the  bones  of  the  neck,  there  are 
eight  pair, — from  between  the  joints  of  the  spine, 
twelve  ; — from  the  loins,  five  pair  more  ; — and  the 
sacrum  or  last  bone  of  the  vertebral  column,  five  more,  — 
making  a total  of  thirty-nine  sets  of  nerves,  from  the 
brain  and  spinal  cord. 


ANATOMICAL  CLASS  BOOK. 


165 


Fig.  67. 


166 


ANATOMICAL  CLASS  BOOK. 


Explanations  of  Fig.  67. 

A A.  Cerebrum,  or  brain. 

B B.  Cerebellum , or  little  brain. 

C C.  Crurd  Cerebri,  or  union  of  the  fibres  of  the  brain. 

D D.  Crura  Cerebelli,  union  of  the  two  sides  of  the  little  brain. 

E E E.  Spinal  marrow. 

1 1.  Branches  of  the  5th  of  nerves,  so  often  noticed  in  this  work. 

2 2.  Branches  of  the  sub-occipital  nerves. 

3 3.  Branches  of  (he  four  inferior  cervical  nerves,  and  the  first 
dorsal,  forming  the  axillary  plexus,  from  whence  all  the  nerves  of 
the  arm  and  fingers  have  their  origin. 

4 4 4 4.  Branches  of  the  dorsal  nerves. 

5 5.  Lumbar  nerves. 

6 6.  Sacral  nerves. 

THIRTY  PAIR  OF  SPINAL  NERVES. 

These  are  first  divided  into  Eight  pair  of  Cervical, 
coming  out  between  the  bones  of  t he  neck,  on  either  side, 
from  the  spinal  marrow,  — to  be  distributed  to  the  muscles. 

Twelve,  pair  of  Dorsal, — in  like  manner,  coming  out 
between  the  dorsal  vertebrae  of  the  back. 

Five  pair  of  Lumbar,  — from  between  the  lumbar  or 
joints  of  the  loins. 

Five  pair  of  Sacral,  — being  a branch  or  termination 
of  the  spinal  marrow  in  the  os  sacrum.  Several  cords, 
coming  through  the  several  openings,  unite  to  form  the 
great  sciatic  nerve  of  the  leg. 

Another  circumstance  should  not  be  lost  sight  of  in 
this  general  survey  of  these  organs  — viz.,  the  well  estab- 
lished fact,  that  two  threads  may  arise  from  the  same  root, 
and  yet  they  sustain  widely  different  offices  in  the  econo- 
my : one  may  contribute  to  the  contraction  of  a muscle, 
while  the  other  carries  the  mandate  for  its  relaxation. 

We  are  warranted  in  believing,  that  even  in  a minute 
nerve,  which  appears  a single  cord,  that  a number  of  dis- 
tinct parallel  filaments  are  lying  side  by  side,  enveloped 
in  the  same  tissue,  whose  functions  are  widely  different 
from  each  other. 

Of  the  nine  pair  of  nerves  from  the  brain,  let  us  pursue 


ANATOMICAL  CLASS  BOOK. 


167 


them  to  their  ultimate  destination,  not,  however,  with  the 
vain  expectation  of  ascertaining  how  it  is  that  they  exert 
an  influence,  but  simply  to  contemplate  the  broad  chart  of 
sympathies  which  is  thus  spread  for  distributing  and  con- 
trolling that  vitality  which  is  so  essential  to  order,  to  con- 
sciousness and  to  physical  perfectibility. 

First  — the  olfactory  nerves,  taking  their  rise  in  the 
brain,  having  gone  but  little  way  within  the  skull,  arrive 
at  the  top  of  the  nose,  where  they  suddenly  divide  into  in- 
numerable hair  drawn  threads,  which  are  lost  in  the  lining 
membrane  of  the  nose. 

The  second,  are  the  optic  — expanding,  when  they 
have  penetrated  the  globe  of  the  eye,  through  the  back 
side,  into  a thin  web  — properly  named  the  retina,  which 
is  the  seat  of  vision. 

In  this  instance,  arising  from  the  same  substance  as 
the  olfactory  to  all  human  appearance,  is  a nerve  which 
can  only  be  influenced  by  the  presence  of  light. 

When  the  nervous  system  is  agitated  by  disease,  even 
in  the  darkest  apartment,  the  participation  which  the 
optic  nerve  has  with  the  diseased  action  of  the  whole,  pro- 
duces the  sensation  of  vision,  and  nothing  else.  If  it  can- 
not be  the  bearer  of  this  one  item  of  intelligence,  it  can 
do  nothing  at  all.  If  anot  her  sensation  is  to  be  conducted 
to  the  mind,  — even  if  it  relates  to  a moat  on  the  face  of 
the  eye,  another  set  of  nerves,  entirely  independent  of  the 
optic,  must  be  the  bearers.  There  is  no  property  in  com- 
mon ; no  relationship  allowing  the  one  to  perform  the  func- 
tions of  the  other  ; yet  they  both  seem  to  possess  the  same 
general  structure,  the  same  component  parts,  and  have  an 
origin  from  the  same  fountain-head,  and  depend  for  their 
vitality  upon  the  same  circulation. 

The  third  nerve  is  generally  distributed  to  the  muscles 
of  the  eye,  to  give  guidance  to  several  of  them. 

Further — the  fourth  nerve,  arising  from  the  brain, 


168 


ANATOMICAL  CLASS  BOOK. 


long,  slender,  and  hair-like,  is  dispensed  altogether  upon 
one  muscle,  the  one  which  rolls  the  eye  downward  towards 
the  shoulder. 

The  fifth  nerve  is  the  most  intricate  to  understand. 
Lying  almost  in  contact  with  the  great  artery  of  the  brain, 
in  the  base  of  the  skull,  the  single  cord  spreads  itself  out 
into  the  form  of  a reddish,  fleshy  pad,  from  which  three 
distinct  cords,  all  distinguished  for  their  size  have  an 
origin.  One  of  the  three  darts  towards  the  eye,  where  it 
commingles  with  those  we  have  been  describing.  The 
second  branch,  creeps  through  an  orifice,  and  having 
reached  the  back  part  of  the  upper  jaw,  sends  on  a lash 
of  fine  lines,  which  find  an  entrance  into  the  substance  of 
the  bones,  and  there  furnishes  the  root  of  each  tooth  with 
one  of  them. 


Fig.  68. 


Explanations  of  Fig.  6S. 

This  plato  will  give  some  general  idea  of  the  intricacy  of  the 
nerves  about  the  face  ; the  most  difficult  part  of  the  neurology  of  the 
head  is  concealed  by  the  bones,  though  we  have  adverted  to  the  in- 
dividual nerves,  which  have  their  origin  in  the  brain. 


ANATOMICAL  CLASS  BOOK. 


169 


2.  The  optic  nerve,  nerve  of  vision,  second  in  the  order. 

3.  Motor  oculi,  or  third  pair,  arising  from  the  brain. 

4.  Trochlearis,  fourth  pair. 

5.  Trigemini,  with  its  three  great  branches,  spoken  of  in  the  text. 

A.  First  division  of  the  5th  nerve,  called  the  opthalmic  branch, 

which  divides  again  into  — 

13.  C The  Frontal  nerve. 

C.  < The  Lachrymal  nerve. 

D.  (Thd  Nasal  nerve. 

E.  Second  division  of  the  fifth  nerve. 

F.  That  branch  of  it  going  to  the  teeth  and  skin  of  the  upper  jaw. 

G.  A ganglion. 

II.  Branches  going  to  the  palate  and  throat. 

I.  Videan  nerve. 

6.  Sixth  nerve  of  the  brain. 

K.  Origin  of  the  Great  Sympathetic  Nerve,  spoken  of  in  the  text. 

L.  Its  additional  organ,  from  the  Videan  nerve. 

M.  Superior  or  first  ganglion  of  the  Sympathetic  nerve. 

N.  Th  ird  division  of  the  fifth  nerve. 

O.  First  division  of  the  third  branch  of  the  fifth  nerve,  going  to  the 
tongue  ; this  nerve  is  the  organ  of  taste. 

P.  A branch  of  the  Gustatory , or  tasting  nerve,  going  to  the  ear 
and  crossing  the  drum. 

Q.  That  division  of  the  fifth  nerve,  which  supplies  the  teeth  of  the 
under  jaw,  and  finally  comes  out  on  the  chin,  to  supply  the  muscles 
of  expression. 

7.  Seventh  pair  of  nerves  from  the  brain,  or.  auditory,  being  the 
nerve  of  hearing. 

Perhaps,  with  all  our  care,  the  reader  will  scarcely  understand 
the  scheme  which  has  here  been  presented.  It  is  not  our  object  to 
be  so  minute  as  to  weary,  and  yet  we  desire  to  be  sufficiently  par- 
ticular to  be  useful. 

The  third  branch  makes  its  way  out  of  the  head,  and 
directs  its  course  to  the  inner  side  of  the  angle  of  the  under 
jaw,  where  it  enters  a smooth  canal,  and  in  like  manner 
furnishes  each  of  the  fangs  of  the  under  teeth  with  a mi- 
nute nerve. 

A recollection  of  the  origin  of  the  dental  nerves,  will 
explain  the  reason  why  a sound  tooth,  in  the  opposite  jaw, 
sympathizes  with  the  pain  of  a diseased  one. 

To  the  eye  again  the  sixth  nerve  goes.  Such  a liberal 
supply  of  nervous  influence  as  is  thus  given  to  this  one 
organ,  argues  very  clearly  its  importance.  In  no  other 
portion  of  the  machine  is  there  a parallel  distribution  of 
nerves. 


15 


170 


ANATOMICAL  CLASS  BOOK. 


The  seventh  is  a double  nerve  : — two  cords,  quite  in 
contact,  the  one  hard  and  tile  other  soft,  strike  the  extremity 
of  that  portion  of  the  temporal  bone,  within  the  skull,  con- 
taining the  beautiful  apparatus  of  the  ear.  One  of  them 
is  expended  upon  the  inside,  and  is  the  acoustic  nerve  : 
the  other  pays  no  regard  to  the  ear,  but,  working  through 
the  solid  bones,  shows  itself  on  the  cheek,  very  near  the 
middle  of  the  external  ear. 

What  circumstance  of  organization  prepares  these 
nerves,  arising,  if  not  at  the  same  point,  at  least  from  the 
same  mass,  for  performing  such  opposite  functions,  as 
hearing  and  feeling,  must  long  remain  an  inexplicable 
paradox. 

Still  further  in  the  series,  comes  the  eighth  pair,  or  par 
vagutn  — sliding  out  at  the  base  of  the  skull,  in  company 
with  the  internal  jugular  vein.  Coursing  down  the  side 
of  the  neck,  it  dips  into  the  chest,  running  through  its 
whole  extent,  and  finally  shows  itself  in  the  cavity  of  the 
abdomen.  From  its  first  exit  from  the  brain,  it  drops  off 
twig  after  twig,  nearly  at  right  angles,  for  the  superficial 
muscles  on  the  throat,  and  the  vocal  tube  ; to  the  larynx; 
to  the  wind-pipe;  the  lobes  of  the  lungs  on  either  side; 
to  the  heart ; the  great  blood-vessel  of  the  body ; to 
the  stomach,  liver,  spleen,  kidneys;  and  to  all  appear- 
ance, neglects  no  viscera  in  any  of  the  great  cavities.  No 
other  nerve,  but  the  sympathetic,  seems  to  have  such  exten- 
sive relations,  nor  is  any  one  of  more  consequence  to  or- 
ganic life. 

Reflect,  for  a moment,  on  the  extraordinary  offices  of  this 
one  nerve.  Both  vessels  and  muscles  on  its  first  appear- 
ance, mutually  depend  upon  its  influence.  Next,  a class 
of  involuntary  muscles  within  the  vocal  box,  cannot  be 
varied  in  their  contractions  without  its  presence.  Even 
the  vibration  of  the  vocal  cords,  the  instruments  of  voice, 
would  be  unserviceable  without  it  : the  lungs  would  faul- 


ANATOMICAL  CLASS  BOOK. 


171 


ter — the  stomach  become  idle  — the  liver  rebel  — the 
intestinal  mechanism  stop  — and  a universal  failure  of 
all  the  vital  apparatus  would  inevitably  ensue. 

One  more  — the  ninth  — the  lingual  nerve , closes  the 
series  from  the  brain.  Without  it  there  would  be  no 
ability  for  moving  the  tongue. 

Let  us  re-examine  the  scheme  of  the  nerves  arising 
from  the  spinal  marrow. 

That  prolongation  of  the  brain,  which  lies  in  the  canal 
of  the  spine,  gives  out  two  sets  of  nerves,  as  from  the  two 
sides  of  the  brain,  but  vastly  larger  in  size.  Besides  be- 
ing large,  several  of  them  unite  together,  so  closely,  that 
it  is  really  difficult  to  separate  them,  for  the  purpose,  it  is 
supposed,  of  establishing  a wide  circle  of  sympathies,  and 
a combination  of  influence  upon  the  muscles.  Notwith- 
standing the  apparent  confusion,  the  most  exact  order  is 
maintained. 

No  man  has  been  competent  to  an  explanation  of  this 
complex  mechanism.  Though  emanating  from  a condens- 
ed part  of  the  brain,  in  which  the  intellectual  operations 
are  not  admitted  to  be  in  force,  a class  of  nerves  have  an 
origin,  which  are  under  the  most  complete  subjection  to 
another  portion  of  the  same  substance.  So  it  is  in  re- 
spect to  all  the  dorsal,  lumbar  and  sacral  nerves. 


172 


ANATOMICAL  CLASS  BOOK. 


Explanations  of  Fig.  69. 

This  plan  shows  the  distribution  of  some  ol  the  nerves  of  the  arm. 

a a.  Tire  cephalic  vein,  running  between  the  pectoralis  rpajor  and 
deltoid  muscle. 

6.  The  basilic  vein. 

c.  The  vena  rnediana  longa,  sending  off. 

d.  The  median  basilic  vein. 

e.  The  median  cephalic  vein. 

/.  The  internal  cutaneous  nerve. 

g.  The  external  muscular  cutaneous  nerve. 

h.  A lymphatic  gland. 

i.  The  fasica  covering  the  muscles  of  the  upper  arm. 

k.  The  pectoralis  major. 

l.  The  deltoid  muscle. 

These  considerations  are  curious  in  themselves,  and  in 
the  mechanic,  the  scholar,  and  the  philosopher,  excite  an 
ardent  desire  fo  comprehend  the  reason  for  the  one,  and 
the  cause  of  the  other.  All  the  boasted  and  lofty  preten- 
sions of  philosophy  are  inadequate  to  the  solution  of  these 
problems  in  the  laws  of  the  animal  economy. 


ANATOMICAL  CLASS  BOOK. 


173 


GREAT  SYMPATHETIC  NERVE. 

As  a point  of  union  between  the  nerves  of  the  brain 
and  those  of  the  spinal  marrow,  — to  maintain  a sympathy 
of  connexion  between  the  voluntary  and  involuntary  or- 
gans, is  interposed  the  sympathetic  nerve,  which  traverses 
the  whole  extent  of  the  chest  and  abdomen,  sending  fibres 
in  all  directions,  to  every  viscus  in  the  body.  Thus,  by 
this  one  nerve,  a mutual  dependence  is  preserved  among 
all  the  various  portions  of  the  living  system. 

Nerves  are  certainly  the  organs  of  our  senses.  How, 
by  the  application  of  bodies  to  the  different  parts,  a sensa- 
tion is  produced,  will  never,  we  fear,  be  clearly  explained, 
nor  can  we  account,  for  a corresponding  change  in  the 
brain,  to  produce  an  idea.  Neither  is  it  known  how  sen- 
sation is  conveyed  by  the  nerves  to  the  brain. 

Sensation  is  a property  peculiar  to  the  nervous  fibre,  as 
irritability  is  to  the  muscle. 


15* 


174 


ANATOMICAL  CLASS  BOOK. 


Q U E STIONS. 


Is  the  brain  a solid  mass,  within  the  skull  ? 

How  is  it  divided  ? 

What  are  the  hemispheres  of  the  brain  ? 

What  do  you  understand  by  the  lobes  of  the  brain  ? 

How  many  coats,  or  coverings  has  the  brain  ? 

Where  is  the  little  brain  or  cerebellum  found  ? 

Where  is  the  spinal  marrow  ? 

What  is  the  use  of  the  spinal  marrow  ? 

Where  do  the  nerves  of  sense  arise  ? 

How  many  nerves  arise  from  the  brain  P 
How  are  the  nerves  protected  ? 

How  many  nerves  arise  from  the  spinal  marrow  ? 

How  are  they  classified  P 

How  are  external  sensations  conveyed  to  the  brain  ? 

Where  is  the  optic  nerve  found? 

Where  are  the  olfactory  nerves  ? 

Are  there  cavities  in  the  substance  of  the  brain  ? 

What  are  the  cavities  called  ? 

What  is  the  supposed  use  of  those  cavities  ? 

What  is  the  consequence  of  dividing  a nerve  ? 

Which  is  the  seat  of  intellect,  the  large  or  small  brain? 
Can  the  brain  be  wounded  with  impunity  ? 

How  does  the  sympathetic  dilfer  from  other  nerves  ? 

What  is  neurology  ? 

Is  there  a correspondence  in  the  structure  of  the  brain  and 
nerve  ? 


ANATOMICAL  CLASS  BOOK. 


175 


THE  SENSES. 


The  senses  are  divided  into  internal  and  external.  The 
internal  are  ideas,  which  the  mind  forms — and  may  be 
produced  by  the  agency  of  the  external  senses,  or  other- 
wise excited,  as  memory,  imagination,  conscience,  and  the 
passions. 

EXTERNAL  SENSES. 

Hearing,  Seeing,  Feeling,  Smelling,  and  Tasting. 

THE  EAR. 

The  ear,  that  organ  by  which  we  are  made  sensible  of 
the  impression  of  sound,  is  a very  complicated  instrument, 
and  a beautiful  piece  of  mechanism. 

It  is  a curious  circumstance  in  the  economy  of  organized 
beings,  that  the  central  portion  of  the  human  ear,  termed 
the  saculus  vest ib n li,  hereafter  to  be  described,  is  the  basis 
of  the  apparatus  of  hearing  in  all  animals,  with  the  excep- 
tion of  insects,  but  becoming  more  and  more  complex  as 
inferior  grades  approximate  the  physical  perfectability  of 
man. 

Sound  being  a vibratory  motion  of  the  air,  first  put  in 
motion  by  a solid  body,  is  collected  by  the  ear,  as  the  pul- 


176 


ANATOMICAL  CLASS  BOOK. 


sations  travel  onward,  and  transmitted  directly  to  the  au- 
ditory nerve.* 

Those  beings  only,  which  are  denominated  locomotive, 
having  the  power  of  moving  themselves  from  one  place  to 
another,  have  an  ear.  Without  this  sense,  of  such  vast 
importance  to  man,  inferior  tribes  would  be  constantly  ex- 
posed to  dangers  and  even  destruction.  Nature  has  not 
been  neglectful  in  granting  the  necessary  means  of  hap- 
piness to  every  being,  in  proportion  to  its  wants  in  the 
sphere  in  which  it  is  destined  to  live;  nor  partial  to  man, 
in  the  development  of  all  his  senses,  to  the  exclusion  of 
other  animals,  whose  physical  propensities,  necessities  and 
circumstances  are  of  as  much  importance  to  them,  in  the 
scale  of  existence,  as  his  own. 

EXTERNAL  EAR.* 

That  appendage  termed  auricula,  'pinna  or  external  ear, 
divested  of  the  skin,  is  a thin,  delicate  piece  of  cartilage, 
quite  elastic,  and  bearing  some  resemblance,  in  this  re- 
spect, to  parchment.  On  its  outer  surface,  it  is  concave, 
but  thrown  into  deep  semicircular  grooves,  which  termi- 
nate in  one  large  dish,  surrounding  the  canal  that  enters 
the  bones,  called  concha,  because  it  resembles  a shell. 
The  lines  or  eminences,  lying  between  the  furrows,  have 
definite  names,  as  helix,  antihelix,  tragus  and  antitragus, 
and  lastly,  the  fat  pendulous  portion,  on  the  under  edge  of 
the  ear, — in  which  trinkets  are  worn,  in  civilized  society, 
in  humble  imitation  of  genuine  savage  life,  — the  lubus. 

* The  antenna;  of  insects  are  considered  the  only  organs  that  con- 
vey a sensation  analogous  to  hearing.  By  the  vibrations  communi- 
cated to  the  body,  through  these,  they  are  probably  made  suscepti- 
ble of  simple  sonorous  impressions. 


So  called  from  aura , ah. 


ANATOMICAL  CLASS  BOOK 


177 


Fig.  70. 


Explanations  of  Fig.  70. 

This  is  a well  marked  ear  of 
a man,  drawn  from  life, 
o to  e — The  helix,  forming 
the  rim. 

a- — The  upper  end  or  com- 
mencement of  the  rim,  slop- 
ing into  the  concha. 
b — Part  of  the  edge  lost  in 
the  face. 

c,  d — Prominent  from  the 
head. 

e — The  fold  terminating  in 
the  lobule  of  the  ear. 
f to  m — The  antihelix. 
f,g  — The  upper  end  divid- 
ed into  two  ridges,  — h the 
union  of  them,  — f and  g. 
i,  k - — lower  end  of  the  anti- 
helix,  continued  at  i into 
the  concha,  and  at  k into 


the  antitragus. 

I — The  tragus  covering  the  entrance  to  the  ear  — like  a post  at 
the  corner  of  a street,  to  prevent  sudden  injury. 
m intitragus. 

n — Lobe  of  the  ear,  usually  bored. 

o,  o — Furrow  between  the  helix  and  antihelix. 

p — The  boat  like  depression  between  the  lines  of  the  antihelix. 

x — The  concha. 

r — The  beginning  of  the  meatus  auditorious,  or  canal. 


MUSCLES. 

Although  in  the  human  species  there  are  muscles  which 
seem  at  first  sight  to  have  been  designed  for  moving  the 
ear  in  different  directions,  their  office  is  expressly  to  keep 
it  tense,  — equally  on  the  stretch  at  all  points,  to  increase 
its  vibratory  property.  Occasionally,  individuals  are  seen 
who  have  such  development  of  the  muscles,  as  to  be  able 
to  move  their  ears  at  pleasure.  Wags  and  buffoons  are 
sometimes  expert  in  the  exercise.  There  are  three  of 
these  muscles. 


178 


ANATOMICAL  CLASS  BOOK. 


Fig.  71. 


In  this  plate  is  represented  the  muscles  peculiar  to  the  external 
ear.  a,  d,  e,  the  cartilage  of  the  ear,  as  seen  on  that  side  looking 
towards  the  head. 

The  attolens  aurem,  or  lifter  up  of  the  ear,  marked  l,  in,  shows 
where  it  becomes  tendinous  on  the  bones  of  the  head,  o,  p,  attach- 
ed to  prominences 

g to  t the  anterior  auris,  placed  between  the  face  and  ear.  q,  r. 
the  portion  of  it  connected  to  the  muscle  of  the  forehead,  growing 
narrower  at  s,  and  inserted  into  (he  helix  at  t. 

u,  z Two  muscles,  or  rather,  two  portions  of  one,  retrahentes  au- 
rum,  to  draw  the  ear  hack  from  the  face. 

u,  v,  w,x,  The  upper  or  larger  portion,  consisting  of  fleshy 
fibres,  u,  v , w. 

y,  z,  The  inferior  portion  of  the  same  muscle. 

All  such  animals  as  keep  their  ears  habitually  erect,  as 
the  fox,  lynx,  cat,  horse,  ox,  ass,  and  various  species  of 
the  dog,  maintain  them  in  that  position  by  the  strength  of 
the  muscles,  which  are  under  the  control  of  the  will. 

It  is  necessary  for  safety  on  the  one  hand,  or  success  in 
seizing  prey,  by  surprise,  on  the  other,  for  the  animal  to 
have  a distinct  auricular  perception,  accompanied  by  a 
nice  sense  of  smell.  By  remaining  perfectly  quiet,  the 
ears  are  directed  to  and  fro,  as  circumstances  may  require, 


ANATOMICAL  CLASS  BOOK. 


179 


to  receive,  most  favorably  and  forcibly  the  sonorous  rays, — 
without  being  obliged  to  move  the  head.*  Elephants, 
hounds,  besides  an  almost  endless  catalogue  of  mammalia, 
have  pendulous  ears,  as  though  the  design  was  to  defend 
the  orifice  ; — in  these  examples,  the  muscles  are  small,  as 
they  are  in  man. 

Birds  have  but  a slight  rim,  approaching  in  outline,  the 
pinna  : lizards,  of  which  there  are  about  forty  varieties, 
serpents  and  other  reptiles,  have  nothing  externally  re- 
sembling an  ear  : in  some,  it  is  difficult,  on  close  examin- 
ation, to  discover  the  precise  spot  where  the  ear  is  located. 
Fishes  are  also  destitute  of  an  external  organ  ; and  yet  all 
these  families,  including  the  amphibious,  as  frogs,  turtles 
and  the  like,  have  a beautifully  constructed  internal  ear,  as 
remarkable,  so  far  as  a mechanical  arrangement  of  parts  is 
concerned,  in  conveying  the  pulsation  of  sound,  as  that 
of  the  most  favored  musician. 

EAR  TUBE.f 

When  the  temporal  or  side  bone  of  the  head,  contain- 
ing, entirely,  the  internal  ear,  is  carefully  sawed  in  twain, 
the  canal,  of  which  we  are  speaking,  will  be  found  about 
three  quarters  of  an  inch  in  length,  and  somewhat  con- 
tracted towards  its  inner  extremity  — and,  on  an  average, 
a little  less  than  a quarter  of  an  inch  in  diameter.  This 
passage  is  a gentle  curve,  as  the  tube,  from  the  external 
opening,  rises  upward  ; but  at  half  its  length,  turns  down- 
ward again,  and  there  bulges  out  in  shape,  something  like 

* It  is  a favorite  opinion  of  the  author,  that  an  ear  trumpet  for  deaf 
people,  instead  of  being  like  the  funnel  of  a common  bugle,  should 
have  a broad  plate,  grooved,  and  indeed,  wrought  in  exact  imitation 
of  the  external  human  ear,  it  being  certain  that  this  is  the  best  mode 
of  directing  sound  into  the  head,  or  nature  would  have  constructed 
it  differently, 

t In  books,  termed  the  Meatus  uuditorius  externus, — simply 
meaning  the  external  passage  to  the  inner  cavities. 


180 


ANATOMICAL  CLASS  BOOK. 


the  bowl  of  a spoon.  A delicate  rim,  like  a moulding-, 
rises  on  the  edge  of  this  expanded  mouth,  for  sustaining 
the  drum  head,  soon  to  be  noticed,  very  much  like  the 
method  of  nailing  a hoop  within  the  mouth  of  a barrel, 
near  the  chime,  to  keep  the  head  from  falling  in.  To  af- 
ford greater  surface,  that  the  drum  head  may  be  consider- 
ably larger  than  the  extremity  of  the  tube  would  allow, 
were  it  stretched  perpendicularly  across,  it  is  sloped,  so 
that  it  requires  an  oval  cover,  under  such  circumstances, 
very  much  larger  than  if  it  were  round,  and  fitted  to  the 
square  end  of  the  pipe.  AH  this  may  be  examined  in  the 
temporal  bone  of  a horse,  sheep  or  dog’s  skull,  as  they  are 
found  bleaching  in  the  fields.  In  these  animals  the  re- 
semblance to  the  human  ear  is  particularly  striking.  The 
common  skin  of  the  face  is  carried  within  the  tube,  for  its 
lining,  but  perforated  in  numerous  places,  by  the  ducts  of 
delicate  little  bags,  lying  between  the  bone  and  skin,  which 
are  constantly  secreting  and  pouring  out  a bitter,  nause- 
ous wax.  The  object  of  this  excretion  is  twofold,  viz. 
first,  to  keep  the  lining  moist  and  pliable,"  and  secondly, 
to  kill  insects  that  may  intrude  there.*  Crossing  this  canal 
from  the  sides,  are  strong  short  hairs,  intersecting  each 
other  in  such  a manner,  that  an  insect  must  overcome  the 
resistance  of  those  pikes,  or  chevaux  de  frise,  in  case  the 
wax  t does  not  arrest  its  progress,  before  reaching  the 

*Ear  wax  is  certain  death  to  insects  that  feed  upon  it;  though  its 
composition  is  such,  that  they  cannot  restrain  their  appetites  when 
pent  up  where  it  is.  Naturalists  have  taken  a hint  from  this,  to 
prevent  ihe  depredations  of  vermin  on  dried  preparations  in  cabinets, 
by  washing  them  in  decoctions  of  aloes  orolher  vegetable  bitters. 

t At  birth  the  tube  is  filled  with  a thick  mucus,  which,  in  some 
children,  unless  speedily  removed,  forms  a cake  of  hard  wax,  com- 
pletely closing  it;  and  by  the  time  the  arliculative  organs  are  devel- 
oped, the  child  is  actually,  deaf  and  dumb.  There  seems  to  boa 
peculiar  predisposition  to  this  in  some  families.  In  others,  children 
after  having  once  talked,  lose  their  hearing  at  four  or  five  years  o t 
age,  and  become  permanently  deaf  and  dumb. 


ANATOMICAL  CLASS  BOOK. 


181 


drum  head,  where  its  peregrinations  are  impassably  lim- 
ited.* 

Fig.  72. 

Explanation  of  Fig.  72. 
This  has  been  an  exceedingly 
difficult  plan  to  execute,  so  as  to 
give  the  exact  relation  of  parts ; 
hence  it  is  very  much  foreshort- 
ened. 

c tod,  — cc,  the  meatus  extcr- 
nus,  as  it  appears,  taken  from 
the  bone ; b,  c,  its  two  cur- 
vatures; — the  first  e;  the 
second  c : — dd,  the  oblique  slant, 
like  a spoon  bowl,  at  the  in- 
ner end,  covered  by  the  drum 
head,  spoken  of  in  the  text. 

e — The  membrana  tympani, 
stretched  on  its  bony  hoop,  bulg- 
ing inward. 

The  remaining  parts,  beyond 
the  boundary  of  the  membrane, 
remain  to  be  described,  although  represented  here  for  the  sake  of 
keeping  up  the  connexion  of  parts  in  the  mind. 

f,g,h,  — The  malleus;  f its  handle;  gits  long  handle;  h the 
head  or  bulb. 

i,  k, — inchus,  or  anvil ; i short,  and  k,  long  processes,  m stapes. 
V,H,A ,m,n,p, — The  labyrinth  ; n,  p,  the  cochlea,  n,  the  be- 
ginning, p,  termination,  in,  the  vestibulum.f 


* When  the  glands  are  diseased  in  consequence  of  a chronic  in- 
flammation, a thin,  purulent  discharge  takes  place,  giving  the  indi- 
vidual, in  some  instances,  trouble,  inconvenience,  and  pain  through 
life.  I have  seen  a skull,  in  which  the  entire  tube,  on  one  side  was 
closed  up  by  a deposition  of  bone.  The  opposite  ear  was  partially 
diseased  in  the  same  manner,  but  the  peculiar  circumstances  of  the 
case,  while  the  person  was  alive,  could  not  be  ascertained. 

t I have  found  considerable  difficulty  in  demonstrating  this  organ, 
without  very  large  models  : — one  now  in  my  cabinet,  made  of  wood, 
magnifies  the  internal  ear  three  feet,  which  can  be  seen  and  under- 
stood at  a distance  in  a large  hall.  Formerly,  when  I taught  anato- 
my in  a Medical  Institution,  it  was  customary  to  suppose  the  col- 
lege an  ear,  and  thus  illustrate  its  intricacies  by  constant  reference 
to  the  apartments  and  passage  ways  of  that  edifice.  Instructors  will 
derive  great  advantage  from  a similar  course  — by  considering  the 
school  house,  when  explaining  the  organ  to  their  pupils,  — the  in- 
ternal ear,  and  the  front  door  the  drum. 


16 


182 


ANATOMICAL  CLASS  BOOK. 


THE  DRUM,  OR  MEMBRANA  TYMPANI.* 

From  the  foregoing  description  of  the  canal,  the  exact 
locality  of  the  drum  head  will  be  understood.  Fitted  to 
the  rim  of  bone,  in  a manner  similar  to  the  parchment 
over  the  barrel  of  a snare  drum,  — it  is  kept  perfectly  tense, 
but  by  an  arrangement  of  the  fibres  peculiar  to  its  organ- 
ization. It  is  oval,  and  somewhat  concave  outwardly,  and 
so  transparent,  that  objects  can  be  seen  through  it,  being 
of  the  color  of  white  oiled  paper;  any  person  of  common 
ingenuity,  can  dissect  this  beautiful  membrane  in  the  head 
of  a dead  fowl,  with  the  point  of  a knife.  It  then  presents 
a striking  resemblance  to  a battledoor.  This  closes  up 
the  extremity  of  the  tube,  in  a healthy  ear  ; notwithstand- 
ing, it  is  frequently  ruptured  by  the  firing  of  heavy  guns, 
inflammation,  and  other  accidents,  without  producing  deaf- 
ness. Across  this  drum,  a fine  thread  of  a nerve  is  drawn, 
called  corda  tympani,  which  gives  it  the  requisite  sensi- 
bility and  connexion  with  the  system.  When  a pin-head 
is  introduced  far  enough  to  touch  the  drum  head,  an  ex- 
quisitely acute  pain  is  the  consequence,  from  pressing  this 
nerve. 

We  have  seen  men  with  the  membranes  ruptured  on 
both  sides,  which  was  inferred  from  the  fact,  that  in  smok- 
ing, they  puffed  the  fumes,  for  amusement,  out  at  their 
ears; — yet  the  sense  of  hearing,  did  not  appear  impaired. 
The  rationale  of  this  will  be  subsequently  explained.  The 
deafness  of  old  people  might  in  some  instances  be  allevi- 
ated by  puncturing  the  membrane,  which,  by  age,  has 
become  thickened  and  inelastic. 

* Lobsters,  crabs,  and,  in  fact,  all  that  remarkable  class  of  animals, 
whose  skeletons  are  outside  of  the  body,  in  the  form  of  a shell,  have 
their  ears  placed  at  the  extremities  of  projecting  points.  The  lob- 
ster’s can  be  detected  at  the  end  of  a short  stump,  near  the  root  of 
the  long  feelers ; — it  consists  of  a perforated  bony  stump,  having  a 
membrane  stretched  over  it,  — covering  a drop  of  fluid,  in  which 
floats  the  auditory  nerve. 


ANATOMICAL  CLASS  BOOK. 


1S3 


No  one  can  be  in  doubt  as  respects  the  office  of  this 
membrane : it  receives  the  sonorous  rays  — having  a broad 
surface,  and  being  on  the  stretch,  is  put  in  vibratory  mo- 
tion by  the  slightest  pulsations  in  the  air,  — which  it 
transmits  to  the  still  more  important  apparatus  within. 

We  have  remarked  that  reptiles  and  fishes  have  no  dis- 
cernible external  orifice  : — the  external  surface  appears 
smooth,  as  though  they  were  destitute  of  this  sense.  Un- 
der the  skin,  however,  and  in  the  bone  answering  to  the 
temporal  one  in  man,  there  is  a round  hole,  — growing 
larger  within.  This  cavity  is  the  tympanum  or  drum  bar- 
rel— answering  to  the  apartment  beyond  the  drum  head, 
in  men  and  quadrupeds.  The  common  skin  which  is  thus 
drawn  over  the  mouth  of  the  tympanum,  acts  precisely  as 
the  drum  head  does,  — vibrating  to  the  least  noise,  with 
exceeding  nicety.  In  the  economy  of  reptiles — those 
scavengers  of  the  earth,  created  to  wallow  in  filth  — at 
the  threshold  of  organic  life,  an  external  opening  would  be 
soon  destroyed,  by  being  filled  with  mud,  gravel  or  insects. 
The  skin  over  the  frog’s  ear  and  the  camelion  is  very 
dense,  shining  and  tremulous.  Frogs,  particularly,  have 
a splendid  circular  piece  of  skin  over  the  tympanum,  just 
back  of  their  large  prominent  eyes.  There  is  a necessi- 
ty for  uncommon  delicacy,  in  their  case,  as  their  ear  is 
constructed  for  hearing  with  equal  precision  in  water  as 
well  as  air.* 

* In  that  class  of  serpents  which  are  covered  with  scales,  the  ex- 
ternal contrivance  of  a tense  skin  over  the  internal  ear,  is  far  infe- 
rior to  the  frog  or  lizard’s  : — to  the  underside  of  a cluster  of  thin 
scales,  wedged  in  the  loose  skin,  a slender  bone,  in  figure  like  the 
pestle  of  a mortar,  runs  into  the  tube,  towards  the  brain,  and  plays 
into  the  fenestra  ovalis. 

All  the  variety  of  serpents  are  distinguished  for  their  delicacy 
in  the  perception  of  sound.  The  boa  family,  particularly,  are 
those  which  exhibit  the  most  satisfaction  in  music.  The  writer 
has  carefully  examined  a boa  constrictor , which  when  fully  grown, 
is  horrible  to  the  sight,  that  was  inattentive  to  sounds,  except  when 
hungry.  At  such  times,  the  scratch  of  a pin  against  the  wall, 


184 


ANATOMICAL  CLASS  BOOK. 


INTERNAL  EAR. 

All  parts  beyond  the  drum-head,  are  collectively  called 
the  labyrinth,  in  consequence,  probably,  of  their  intri- 
cacy. 

To  understand  the  arrangement  of  the  apartments  to 
which  the  reader  is  now  to  be  introduced,  requires  pa- 
tience, as  well  as  close  observation,  or  the  mechanism 
cannot  be  comprehended.  First  the 

DRUM-BARREL,  OR  TYMPANUM. 

Directly  behind  the  membrane  is  a small  room,  of  the  ca- 
pacity of  a common  white  bean.  Its  name  is  derived  from  a 
word,  meaning  a drum,  as  it  is  one  in  office,  but  having, 
instead  of  one  head  like  the  kettle  or  two  as  in  the  snare 
drum,  it  has  three  heads;  — the  largest  of  which  is 
towards  the  outer  ear,  — while  at  the  other  end  of  the 
barrel,  are  two  little  ones. 

Three  distinct  apartments,  one  beyond  the  other,  which 
in  anatomical  works,  have  further  minute  subdivisions, 
collectively  make  up  the  labyrinth.  First,  the  tympanum, 
just  adverted  to  ; secondly,  the  vestibule  ; and  thirdly,  the 
cochlea.  In  connexion  with  these  are  certain  tubes,  hav- 
ing sundry  barbarous,  unintelligible  names. 

Behind  the  ear,  a hard  knob  of  bone  may  be  felt,  with 
the  finger,  (mastoid  process)  on  which  that  muscle  is  fast- 
ened, which,  with  its  fellow  on  the  opposite  side,  brings 
the  head  forward  ; within,  it  is  hollow  — being  full  of  con- 

roused  the  monster  to  unceasing  watchfulness.  The  ear  of  the  land 
tortoise,  and  the  rattlesnake,  do  not  differ  as  much  as  the  physiolo- 
gist might  at  first  suppose  — though  in  the  water  turtle,  constituted 
for  hearing  alternately  in  air  and  water,  there  is  a perceptible  differ- 
ence. In  the  first  a single  bone  is  found;  while  in  the  latter,  in 
addition  to  the  bone,  there  are  fine  chalky  particles,  which  move 
against  each  other,  to  propagate  the  motion  or  noise  in  the  water,  to 
the  ramifications  of  the  nerve. 


ANATOMICAL  CLASS  BOOK. 


185 


ical  cells  resembling  the  spokes  of  a wheel,  growing  small- 
er as  they  unite  in  one  pipe,  which  opens  into  the  drum 
barrel.  Physiologists  agree  that  the  use  of  these  cells  is 
for  reverberating  sound,  that  it  may  gain  strength  by  being 
reflected  from  wall  to  wall,  in  order  to  excite  a stronger 
sensation  when  conveyed  to  the  nerve  : these  are  partic- 
ularly large  in  some  animals.*  A similar  piece  of  me- 
chanism is  discoverable  in  the  cheek  bones,  and  even  the 
centre  bone  of  the  skull,  for  reverberating  and  strengthen- 
ing the  voice.  Lions  have  large  cavities  in  the  bones  of 
their  heads  and  faces,  on  purpose  to  increase  the  intensity 
of  the  vibrations  ; — hence  their  characteristic  roar. 

In  another  direction,  is  the  minute  orifice  of  a cone- 
shaped  pipe,  eustachian  iube,  that  opens  with  a trumpet- 
like extremity  in  the  mouth, — it  being  necessary  to  the 
free  vibration  of  the  drum  head,  that  the  same  quality  of 
air  that  transmits  the  sonorous  pulsations,  should  also  exist 
on  the  opposite  side,  within  the  barrel : the  use  of  the 
eustachian  tube,  (so  called  from  Eustachias,  the  discover- 
er) is  to  admit  it.  Nothing,  therefore,  is  more  completely 
an  imitation  of  the  tympanum  of  the  ear,  than  the  martial 
drum,  which  has  a little  hole  in  the  side,  equivalent  to  this 
we  are  describing,  descending  to  the  mouth,  the  nearest 
point  from  which  atmospheric  air  could  be  taken,  without 
disarranging  or  disturbing  the  functions  of  other  organs. 
By  closing  the  sounding  hole  of  the  drum,  the  music  is 
less  audible  — sounding,  when  the  air  inside  becomes  rare- 
fied, like  music  in  a well.  The  reason  is,  the  equal  bal- 
ance of  air  is  destroyed  : — such  is  the  object  and  office 

* In  a letter  from  the  venerable  Dr  James  Thatcher,  of  Ply- 
mouth, the  following  curious  fact  is  related: 

‘ Reflection  of  Sound.  — A gentleman  told  me,  to-day,  (May  3d, 
1331,)  that  a few  days  since,  he  was  passing  through  one  of  our 
streets  where  there  were  considerable  intervals  between  the  houses, 
a gentleman  totally  blind,  walking  with  him,  assured  him  that  he 
knew  exactly  when  he  was  passing  a building, by  a peculiar  sensa- 
tion in  his  ears,  occasioned  by  a different  concussion  of  the  air.’ 

16* 


186 


ANATOMICAL  CLASS  BOOK. 


of  the  eustachian  tube.  Sometimes,  in  violent  sneezing, 
or  sudden  cough,  the  patulous  mouths  get  stopped  for  an 
instant  with  saliva  ; and  many  readers  are  probably  famil- 
iar with  the  sensation  of  fulness  that  ensues,  — giddiness 
and  ringing  in  the  ears,  to  the  annihilation  of  accurate 
auricular  perceptions,  till  the  cause  is  removed.* 

There  are  many  existing  cases  of  deafness,  having  their 
origin  in  some  such  cause  : the  pipe  finally  inflames,  and 
becomes  permanently  sealed  : a skilful  aurist,  under  such 
circumstances,  will  adroitly  puncture  the  drum  head,  with 
an  instrument  purposly  constructed,  and  relieve  the  patient 
without  pain. 

OVAL  WINDOW,  on  FENESTRA  OVALIS. 

Fenestra  ovalis  means  an  oval  window,  covered  by  one 
of  the  two  little  drum  heads.  Beyond  this,  supposing  a 
person  could  pass  through,  he  would  arrive  in  the  vestibule, 
or  second  room.  Lower  down,  but  a few  lines  from  this, 
is  the  second  little  parchment  head,  called 

ROUND  WINDOW,  OR  FENESTRA  ROTUNDA. 

This  is  a round  window ; were  it  possible  to  tear  it 
away  and  creep  through  the  frame,  the  traveller  would 
enter  into  one  of  the  canals  of  the  cochlea. 

* Notwithstanding  the  fine  arguments  of  writers  to  the  contrary,  I 
believe  that  partially  deaf  persons  hear  better  when  the  mouth  is 
open  ; instinctively,  it  may  be  observed,  such  individuals  listen  with 
an  open  mouth.  The  pulsations  of  sound  thus  enter  the  tympanum 
and  set  the  fenestra  ovalis  vibrating,  — but  very  much  less  forcibly 
than  through  the  external  opening,  in  its  healthful  condition. 


ANATOMICAL  CLASS  BOOK. 


187 


Fig  73. 


Explanation  of  Fig.  73. 

In  this  diagram,  the  labyrinth  and  little  bones  of  the  ear,  are  mag- 
nified exceedingly.  This  is  to  show  the  manner  in  which  they  are 
connected,  and  the  order  in  which  they  are  placed. 

a to  e — Th & malleus,  about  to  be  described ; a,  a long  process  ; 
b,  a shorter  one  ; c,  the  handle,  attached  to  the  drum  head  ; d,  the 
neck ; and  e the  head  of  the  malleus,  like  a mallet. 

f to  i — The  inchus  ;f  its  body  : g its  short  leg  ; i the  point  united 
to  the  stapes. 

kton  — The  stapes;  It  its  small  head,  i the  anterior  leg,  n the 
basis  connected  with  the  membrane  which  closes  the  fenestra  ovalis. 

o to  m — The  labyrinth  ; o,  r,  the  first  turn  ot  the  cochlea  ; s,  t,  u, 
v,  the  second  ; w,  x,  the  half  or  third  turn  ; y the  foramen  rotun- 
dum  or  round  window  ; zz,  the  vestibulum  ; ABCD,  superior 
semicircular  canals;  A,  the  ampulla-,  B C,  its  curvature;  D,  its 
union  with  the  inferior  or  posterior  canal ; E F G H,  inferior  canal; 
E,  its  ampulla  ; F G H,  its  curious  curve  and  its  junction  with  the 
first;  I K L M,  the  exterior  canal;  I,  the  ampulla;  K L,  the  direc- 
tion ol  its  curve ; M,  its  termination  in  the  vestibule. 


188 


ANATOMICAL  CLASS  BOOK. 


Fig.  74. 


Explanation  of  Fig.  74. 

In  this,  the  bony  case  of  the  labyrinth,  has  had  one  half  cut  away 
to  exhibit  the  interior. 

a to  l — The  upper  part  of  the  cochlea;  aa,  the  thickness  of  its 
external  shell  in  a foetus  of  eight  months  ; b c d,  the  lamina  spiralis  ; 
be,  scala  vestibuli;  e f gh  i,  the  scala  tympani.  Here  is  seen 
the  bony  lamina  spiralis ; Sits  origin;  d its  termination  in  a little 
hook,  termed  hamulus;  k the  opening  of  the  infundibulum,  where 
the  scaloe  communicate  ; l the  opening  of  the  aqueduct,  or  drain  of 
the  fluids  from  the  cochlea. 

m to  g — The  under  half  of  the  vestibulum;  m the  thickness  of 
its  case  in  the  foetus  ; n the  fovea  or  round  pit ; o an  oval  pit ; p a 
ridge  between  them  ; q opening  of  the  aquaeductus  vestibuli. 

r,  g,  k,l,  — The  canals  divided;  r the  thickness  of  their  case  in 
the  infant ; g the  posterior  ; l exterior  semicircular  canal;  1 opening 
of  the  big  end  of  the  posterior  canal ; 2 opening  of  the  large  end  of 
the  superior  ; 3 the  opening  common  (o  their  united  tubes  ; 4 the 
larger  end  ; 5 the  contracted  opening  of  the  external  canal. 

LITTLE  BONES  OF  THE  EAR,  OR  OSSICULA  AUDITUS. 

Perhaps  there  is  no  insulated  portion  of  an  animal,  that 
more  clearly  and  satisfactorily  evinces  superhuman  design, 


ANATOMICAL  CLASS  BOOK. 


189 


than  the  figure  and  articulation  of  the  four  ear  bones, 
which  we  shall  now  endeavor  to  describe.  The  technical 
phrase  ossicula  auditus , in  the  Latin,  implies  little  bones  of 
the  ear.  They  are  by  far  the  smallest  in  the  body.  The 
first,  in  the  order  of  their  distribution,  is  the  malleus  or 
mallet,  — having  a faint  resemblance  to  that  instrument, 
inasmuch  as  there  is  a long  handle  joined  to  a round  knob. 
Secondly,  the  inchus,  from  its  resemblance  to  an  anvil : — 
os  orbiculare  or  round  bone,  the  least  in  size  that  has  ever 
been  discovered,  — being  in  man  considerably  smaller 
than  a mustard  seed.  And  lastly,  the  stapes  — or  stirrup, 
almost  a miniature  fac  simile  of  a saddle  stirrup.  Birds 
have  but  two  of  these,  of  which  the  malleus  is  most  devel- 
oped. Turtles  have  but  one,  the  malleus  ; and  reptiles, 
as  far  as  personal  dissection  warrants,  have  but  two.  In 
these  classes,  there  is  a departure  in  form,  from  those  we 
are  contemplating  in  our  own  species. 


having  shorter  arms,  is  in  the  same  position  as  in  Figure  73  ; the  let- 
ters have  the  same  reference.  The  star  points  out  the  articulating 
surface  for  the  malleus. 

Any  person  from  the  foregoing  remarks,  will  recognise  the  stapes, 
by  its  shape  — ab  its  head;  c the  neck;  d anterior  crus;  e the 
second; /the  basis. 

The  fourth  drawing  represents  another  view  of  the  stapes,  seen 
from  above  — a its  cartilage  ; b anterior  ; c posterior  ; d the  basis. 


Fig.  75. 


IT)  Here  is  presented  a 
magnified  view  of  the 
ear  bones.  The  os  'or- 
biculare, or  round  bone, 
is  not  represented,  be- 
ing considered  by  some 
as/nly  an  appendage 
of  the  malleus. 


The  malleus  known 
by  its  long  arms ; a,  b, 
c,  d,  e,  mark  the  same 
points  as  in  Figure  73. 
The  inchus,  resem- 
bling a molar  tooth, 


Explanation  of  Fig. 
75. 


190 


ANATOMICAL  CLASS  BOOK, 


As  these  bones  are  placed  in  the  drum  barrel,  one 
joined  to  the  extremity  of  the  other,  they  make  a compound 
lever,  — the  object  of  which  is,  to  have  the  freest  and  long- 
est extent  of  motion,  in  a little  space; — unlike  the  muster 
drum,  which  is  continually  referred  to  on  account  of  fa- 
miliar illustration,  the  sticks  of  this  are  fixed  on  the  inside, 
and  though  no  hands  are  there  to  beat  them  on  the  head, 
they  are  connected  to  little  cords,  which  jerk  them  down 
with  a sort  of  conscious  independence,  whenever  there  is 
the  least  noise  abroad,  to  give  the  brain  intelligence,  as  it 
were,  of  what  is  going  on  without.* 

Fig.  76. 

Explanation  of  Fig.  76. 

In  this  drawing;  the  little  hones  are  represented 
of  their  natural  size,  with  the  exception  of  the  last 
one, — which  is  magnified. 

<m  a 

There  is  some  resemblance  in  the  motion  to  be  effected 
by  this  chain  of  bones,  to  the  up  and  down  motion  of  the 
hand  at  the  extremity  of  the  arm,  viz.  — carrying  one  end 

* There  are  some  diseases  familiar  to  medical  gentlemen,  beside 
local  affections  of  the  ear,  wliich  fix  upon  the  bones  about  the  face. 
Under  such  circumstances,  a sanious  discharge  washes  these  little 
bones  entirely  away  : — nothing  is  more  certain,  than  the  fact,  that 
the  three  first  bones  may  be  corroded  and  floated  from  their  connex- 
ions:— indeed,  extracted  with  forceps,  and  the  patient  hear,  to  all 
intents  and  purposes,  nearly  if  not  quite  as  well  as  he  did  before. 
Thus  the  membrane,  (drum  head)  and  three  out  of  four  bones  are 
unnecessary,  it  seems,  in  the  auditory  apparatus  of  man.  Stripped 
thus,  it  falls  below  the  frog’s  — being  deficient  in  an  external  cover- 
ing ot  vibrating  membrane.  The  vibrations,  in  this  case,  act  directly 
on  the  foot  piece  of  the  stapes.  — which  is  broad  enough  to  offer  re- 
sistance to  the  vibrating  air.  Being  connected  with  the  membrane 
of  the  fenestra  ovalis,  it  produces  a motion  in  it,  which  is  propagated 
to  the  fluid  beyond,  and  thus  the  nerve  becomes  agitated.  If  the 
stapes  could  be  detached  without  rupturing  the  membrane  of  the 
fenestra  ovalis,  then  hearing  could  be  effected  independent  of  the  lit- 
tle bones.  Their  use  is  merely  to  strengthen  the  vibrations  within, 
just  in  the  proportion  that  they  have  a tendency  to  become  faint,  as 
the  distance  increases  from  whence  they  had  their  origin. 


ANATOMICAL  CLASS  BOOK. 


191 


of  the  lever  through  considerable  space,  while  the  other, 
to  which  the  power  is  applied,  has  no  perceptible  motion, 

Small  as  the  osicula  auditus  are,  the  first  and  last  of  the 
series  have  muscles,  called  tensors,  laxators,  &c,  which 
are  susceptible  of  demonstration.  Rough  points  and  pro- 
jections on  the  inside  of  the  tympanum,  give  attachment 
both  to  -the  muscles  and  the  bones  themselves.  Even 
these  minute  points,  the  old  anatomists  have  belabored  with 
what  they  supposed  significant  names.  One  end  of  the 
malleus,  the  handle,  is  connected  with  the  inside  of  the 
membrana  tympani ; the  other  is  fitted  into  a socket  of  the 
inchus — and  that  articulated  with  the  orbiculare  or  round 
bone,  — which  stands  as  a medium  of  connexion  between 
the  two. 

Such  is  the  mechanical  adaptation  of  one  of  these  bones 
to  the  other,  that  if  the  extreme  point  of  the  handle  of  the 
malleus  be  moved  the  millionth  or  ten  millionth  part  of 
an  inch,  by  the  vibrations  of  the  drum  head,  it  will  so  ope- 
rate on  the  inchus  and  that  on  the  stapes,  through  the  in- 
tervention of  the  orbiculare,  that  the  last  bone  will  move 
through  treble  the  space,  by  a single  sonorous  pulsation  of 
the  malleus,  in  the  same  period  of  time.  In  fact,  the 
stirrup,  in  plain  language,  is  exactly  fitted  into  the  oval 
window,  like  the  box  of  a pump,  so  that  a motion  given  to 
the  handle  of  the  malleus,  operates  on  the  chain,  to  effect 
the  stapes,  that  it  may  work  backward  and  forward,  with 
the  same  motion  and  on  the  same  principle  of  the  work- 
ing of  the  piston  of  a syringe.  To  hear,  it  is  necessary 
that  the  stapes,  attached  to  the  parchment  window,  should 
move  to  and  fro. 

ENTRY,  OR  VESTIBULE. 

This  word  implies  an  entry,  — being  an  intermediate 
apartment  between  the  tympanum  and  cochlea ; in  the 


192 


ANATOMICAL  CLASS  BOOK. 


sense  in  which  it  is  now  received,  it  is  a hall  of  the  edi- 
fice beyond,  — from  which  doors  are  opening  into  various 
winding  passages.  Its  length  and  diameter  are  not  far 
from  those  of  a grain  of  wheat ; — as  in  a preceding  para- 
graph, if  we  suppose  an  individual  has  torn  away  the  stapes, 
stretched  across  the  oval  window,  and  then  cut  away  the 
latter,  to  wend  his  way  into  the  vestibule,  he  will  find  it  a 
long  but  narrow  room.* 

On  one  side  he  will  discover  three  holes,  and  on  the 
opposite,  only  two,  which  are  the  openings  or  communi- 
cation of  the  semicircular  canals,  with  the  vestibule.  With- 
in this  vestibule,  are  two  sacs,  water  tight,,  containing  a 
clear  fluid.  Though  there  is  no  communication  between 
them,  the  quality  of  the  fluids  distending  them,  is  alike 
-—one  is  considerably  larger  than  the  other,  and  both 
together,  would  not  equal  in  bulk,  two  good  sized  pin- 
heads. The  one  of  the  greatest  magnitude,  is  called  the 
alveus  communis  or  the  union  of  rivers  — from  the  circum- 
stance that  the  canals  were  thought  to  resemble  streams 
of  water,  having  a free  communication  with  the  water  in 
the  reservoir.  Saculus  Cochlea,  the  lesser  one,  though 
separated  from  the  other  by  the  thickness  of  its  own  and 
the  other’s  wall,  is  eked  out  into  a long  gyrating  tube,  that 
traverses  the  cochlea. 

This  large  sac,  alveus  communis,  is  the  elementary  one 
found  in  polypi  — and  it  is  this  that  is  built  uponjfrom  one 

* If,  by  any  circumstance,  the  membrane  of  the  oval  window  or 
fenestra  ovalis,  is  ruptured,  the  fluid  of  the  labyrinth  will  certainly 
escape.  This  constitutes  incurable  deafness.  No  operation,  no  pre- 
scription can  avail,  as,  in  the  constitution  of  things,  the  acoustic  nerve 
cannot  be  acted  upon  in  any  other  way,  than  through  the  agitation 
of  the  fluid  which  surrounds  it.  Dr  Darwin  was  of  opinion  that 
if  a deaf  person  dreamed  of  hearing,  the  internal  parts,  essential  to 
the  function,  were  unimpaired.  The  same  remark  is  applicable  to 
the  blind.  I have  invariably  found  that  the  incurably  deaf  as  well  a3 
incurably  blind,  never  dream  of  hearing  or  seeing.  This  clearly 
shows  a destruction  of  the  sense,  inasmuch  as  the  imagination  cannot 
rouse  a single  vestige  of  their  former  activity. 


ANATOMICAL  CLASS  BOOK. 


193 


species  to  another,  till  perfected  in  the  complicated  machi- 
nery of  the  human  ear. 

Besides  the  sacs  themselves,  the  porch  is  lined  with  a 
membrane  of  exquisite  texture,  in  which  is  conducted 
the  vessels  that  administer  the  blood  to  the  contained 
reservoirs,  and  also  secrete  their  contained  fluid,  aqua 
labyrintha  or  water  of  the  labyrinth,  further  to  be  com- 
mented upon. 

SEMICIRCULAR  CANALS. 

These  are  properly  a prolongation  of  the  vestibule  — 
the  design  evidently  being  to  furnish  surface  for  expand- 
ing the  auditory  nerve,  without  carrying  it  onward  towards 
organs  that  would  be  affected  by  their  presence.  No 
way  could  be  devised,  more  strictly  economical,  than  to 
have  a circular  or  semicircular  canal,  — curving  in  a little 
space,  as  in  a very  small  solid  bit  of  bone.  Precisely  on 
this  plan,  are  these  canals  — they  are  three  in  number. 
Let  it  be  remembered  in  this  place,  that  the  tympanum 
including  the  vestibule,  little  bones  and  semicircular 
canals,  exclusively  make  up  the  ear  of  Ashes,  and  rep- 
tiles— neither  of  these  tribes  having  an  external  ear,  nor 
the  cochlea,  which  still  remains  to  be  elucidated. 

So  much  is  necessary  to  the  perception  of  simple 
sounds  : the  cartilaginous  fishes,  (sharks,  eels,  &c,)  have 
the  canals,  and  are  therefore  capable  of  judging  of  the 
direction  and  condition  of  different  sounds.  The  Chinese 
drive  fish  from  the  crevices  of  rocks  to  the  angling  ground, 
by  beating  a gong.  Pike  and  carp,  reared  in  artificially 
stocked  ponds,  both  in  Poland  and  France,  have  been 
taught  to  come  to  a particular  spot  to  feed,  at  the  ringing 
of  a bell.  Serpents,  abundant  evidence  substantiates,  are 
exceedingly  excited  by  the  lively  strains  of  music  — coil- 
ing themselves  into  a variety  of  folds,  and  giving  a tremu- 
17 


194 


ANATOMICAL  CLASS  BOOK. 


lous  vibration  to  the  tail,  which  long  experience  proves  to 
be  the  result  of  a pleasurable  sensation,  and  not  one  of 
displeasure,  rage  or  pain. 

Two  of  these  canals,  as  they  wind  towards  the  side  of 
the  vestibule,  coalesce  — and  when  they  perforate  the 
wall,  have  only  one  orifice  in  common.  The  third  enters 
alone,  and  this  explains  the  two  holes  seen  on  one  side  of 
the  vestibule;  on  the  opposite  side  are  three,  being  the 
orifices  of  the  same  three  canals,  opening  singly.  When 
the  semi-circular  canals  are  closely  examined,  they  are 
observed  to  be  larger  at  one  extremity,  near  the  walls  of 
the  vestibule,  than  at  the  other;  the  bulbs  or  bulges  are 
termed  ampullulai  or  bottle  shaped.  A crook-neck  squash 
is  an  exact,  though  greatly  magnified  representation  of 
any  one  of  the  semicircular  canals.  The  diameter  of  the 
circle,  of  which  they  are  a little  more  than  two  thirds  of  a 
segment,  varies  but  little  from  one  quarter  of  an  inch  in 
man  : but  the  calibre  of  the  canals  themselves  will  scarce- 
ly admit  the  introduction  of  a fine  bristle.  A probable 
reason  for  the  swelling  out  of  the  ampullulae  will  be  given 
when  discoursing  particularly  of  the  nerve. 


ANATOMICAL  CLASS  BOOK. 


195 


Explanation  of  Fig.  77. 

In  this  enlarged  diagram  of  the  labyrinth  which  is  laid  open,  the 
soft  parts  are  seen.  Young  gentlemen  pursuing  medical  studies, 
will  derive  the  most  profit  from  this  plan 

a to  e — The  lamina  spiralis  viewed  from  above.  The  distribu- 
tion of  the  nerve  will  not  be  easily  distinguished  I fear  — a a a,  the 
first  turn ; b b,  second  turn  ; c d e,  the  third  turn  of  the  lamina  ; d e, 
where  the  scalse  communicate. 

Comparetti  has  described  the  lamina  to  consist  of  four  different 
substances,  or  zones:  1,  the  bony  zone  ; 2,  coriaceous  ; 3,  vesicula; 
4,  the  membraneous  zone. 

/,  sacculus  sphericus  ; g,  space  btween  that  and  the  alveus  com- 
munis ; h,  alveus  communis  ;1  k i 3,  posterior  canal ; 1 i,  its  am- 
pulla j k,  the  nerve  expanded  over  it ; 2 1 m,  the  superior  canal  ; l, 
the  ampullulae  ; 4 n 5,  the  exterior  canal,  communicating  at  both 
ends  with  the  alveus  communis. 

Within  these  bony  tubes,  are  membraneous  ones,  — 
prolongations  of  the  sacs  found  in  the  vestibule  ; but  they 
are  not  in  contact  with  the  walls  : on  the  contrary,  they 
are  kept  from  them  by  the  interposition  of  a fluid,  whose 
equal  pressure  keeps  them  exactly  in  the  centre.  Further 
to  show  the  exceedingly  minute  structure  of  this  accurate- 


196 


ANATOMICAL  CLASS  BOOK. 


ly  operating  instrument,  it  is  necessary  to  remember  that 
the  membraneous  tube  is  also  distended  with  a transpa- 
rent watery  liquor.  Still  smaller  canals,  running  through 
the  temporal  bone  in  which  the  internal  ear  is  located, 
pour  in  and  discharge  the  old  fluid,  as  an  unceasing 
process. 


SNAIL-SHELL,  OR  COCHLEA. 

The  third  and  last  anatomical  division  of  the  internal 
ear,  is  the  cochlea,  or  snail  shell.  Recollecting  how  the 
canal  of  a snail-shell  winds  about  a central  pillar,  will 
enable  the  reader  to  understand  the  text.  In  the  snail 
shell  of  the  ear,  however,  there  are  two  canals,  side  by 
side,  which  wind  twice  and  a half  round  a central  pillar, 
which  is  hollow,  and  termed  mocliolus.  At  the  apex,  the 
two  canals  open  in  one  common  cavity,  but  a thin  slip  of 
bone  caps  over  both  openings  as  well  as  over  the  top  of  the 
hollow  end  of  the  pillar,  like  a parasol.  This  is  the  cupola, 
in  technical  language.  The  upper  end  of  the  hollow 
pillar  is  broad,  but  becoming  narrower,  the  lower  is  de- 
nominated the  infundibulum  or  tunnel-shaped  extremity. 

After  leaving  the  inner  extremity  of  the  vestibule,  com- 
mences one  canal  of  the  cochlea,  which  becomes  smaller 
and  smaller,  till  it  terminates  under  the  cupola.  Now, 
supposing  the  reader  were  travelling  in  this  canal,  he 
could  step  from  the  termination  of  the  one  we  are  describ- 
ing, over  the  broad  opening  of  the  modiolus , shaded  above 
by  the  cupola,  into  the  mouth  of  the  second  canal.  By 
following  its  turns,  increasing  in  diameter,  as  he  proceeds, 
till  he  has  gone  twice  and  a half  round  the  modiolus,  he 
would  arrive  at  the  fenestra  rotunda  or  round  window. 
This  being  like  parchment,  semi-transparent,  he  could 
look  into  the  tympanum  where  the  little  bones  are  lodged. 

Thus  it  is,  that  one  canal  is  in  reality  a prolongation  of 


ANATOMICAL  CLASS  BOOK. 


197 


the  vestibule,  and  the  other  opens  into  the  tympanum.  A 
fluid  fills  the  canals,  which  is  prevented  from  escaping  by 
the  oval  window,  in  the  vestibule,  in  one  direction,  and 
by  the  round  one  at  the  other.  In  the  centre  of  this  li- 
quor, floating,  are  the  finely  organized  threads  of  the 
acoustic  nerve. 

Those  animals  having  the  power  of  combining  sounds 
to  produce  song,  have  a cochlea,  and  generally,  a corres- 
ponding vocal  apparatus.  Birds,  have  a cochlea,  but  it 
consists  only  of  two  tapering  tubes,  united  at  one  ex- 
tremity, but  diverging  at  the  other,  as  in  man.  A musical 
ear  was  once  thought  to  depend  exclusively  on  a cochlea ; 
but  common  sense  teaches  us,  and  the  fact  is  notorious, 
that  singers  as  well  as  those  who  cannot  sing,  have  ears 
constructed  precisely  alike ; and  therefore,  the  whole 
mystery  depends  on  the  peculiar  development  of  the  brain. 


Explanation  of  Fig.  78. 

Let  it  be  remembered  by  the  reader,  that  part  of 
the  last  as  well  as  the  following  diagram,  which  has 
a sort  of  shell-like  turn,  is  denominated  the  cochlea. 

The  object  of  this  drawing,  is  to  show  the  soft  con- 
tents of  the  labyrinth,  of  their  natural  size  and  in  their 
natural  situation.  All  the  eminences  of  the  temporal 
bone  have  been  broken  away. 

a a,  the  spiral  plate  of  the  cochlea ; b,  the  round  sac,  or  sac  of  the 
cochlea  ; c,  alveus  communis;  g,  the  posterior  ; k,  the  superior,  and 
l the  exterior  semicircular  canal. 


THE  HEARING,  OR  AUDITORY  NERVE. 

There  is  no  part  of  the  intricate  organ  we  have  been 
explaining,  more  absolutely  difficult  to  display  and  to  fully 
understand,  in  all  its  relations,  than  the  nerve  of  hearing, 
and  we  shall  therefore  avoid  all  laborious  descriptions,  and 
merely  generalize. 

The  auditory  nerve  is  the  seventh,  — a pair  precisely 
alike  on  the  two  sides  of  the  brain ; not  much  larger  than 

17# 


198 


ANATOMICAL  CLASS  BOOK. 


cotton  sewing  threads  ; it  enters  the  cochlea  first  through 
a sieve-like  orifice,  on  one  side  of  a bone  that  projects 
from  the  inside  of  the  skull  towards  the  brain.  This  de- 
pression where  the  nerve  enters,  towards  the  external  ear, 
is  the  meatus  auditor  ins  interims.  It  assumes  a variety  of 
shapes  in  distributing  itself  in  the  various  tabes,  sacs,  canals 
and  pits  we  have  been  exhibiting.  At  some  points,  many 
delicate  threads  are  discoverable,  side  by  side : at  others, 
fibres  are  seen  floating  in  the  surrounding  fluid,  from  the 
main  trunk  : at  others,  the  nerve  assumes  the  form  of  a 
flocculent  paste,  and  at  others,  a woolly  texture.  The 
whole,  distributed  thus  elaborately,  constitutes  the  nerve 
of  hearing. 

The  sense  of  hearing  is  not  confined,  in  a healthful  con- 
dition of  the  organ,  to  anyone  particular  part  or  point : 
the  sensation  is  perceived  in  the  whole  at  the  same  instant 
of  time.  It  has  been  recently  demonstrated  that  the  hu- 
man ear  is  so  extremely  sensible,  as  to  be  capable  of  ap- 
preciating sounds  which  arise  from  about  24,000  vibrations 
in  a second  ; and,  consequently,  that  it  can  hear  a sound 
which  lasts  only  the  24,000th  part  of  a second.  The  ques- 
tion now  may  arise,  why  was  it  necessary  to  construct 
such  an  intricate  machine,  if  one  part  of  it  has  not  a high- 
er office  to  sustain  than  another  ? 


ANATOMICAL  CLASS  BOOK. 


199 


Fig.  79. 


Explanation  of  Fig.  79. 

An  enlarged  view  of  the  labyrinth  laid  open. 

a,  b,  c,  — the  cochlea.  To  exhibit  the  zona  mollis,  the  outside  or 
bony  case  is  removed. 

d,  e,f,  — the  vestibulum. 

g,  to  q,  — the  semicircular  canals. 

g,  h,  i,  — the  posterior;  k,  l,  m,  the  superior;  o,p,  q,  the  exterior 
canal. 

1,  2,  3 — the  lamina  spiralis,  seen  on  its  under  surface  ; 3,  the  two 
sacs  so  often  mentioned  in  this  work,  in  the  vestibule,  which,  view- 
ed in  this  plan,  look  like  one. 

t,  u,  — the  membranous  posterior  canal. 

v,w,  x, — the  superior  membranous  canal,  uniting  with  the  last, 
at  x,  y,  z,  the  exterior  membranous  canal. 

This  diagram  exhibits  the  distribution  of  the  acoustic  nerve  in  the 
labyrinth  ; the  large  branch  goes  to  the  cochlea,  and  the  three  oth- 
ers, smaller,  to  the  vestibule,  and  three  semicircular  canals. 

Economy  was  the  object  : — to  pack  as  much  as  possible 
in  the  smallest  space,  is  observable  in  all  animal  mechan- 
ism. No  other  kind  of  arrangement  of  cells  in  the  small 
block  of  bone  in  which  these  are  found,  would  or  could 
have  afforded  so  much  surface  to  spread  out  such  an  ex- 
tent of  nerve.  This  then  is  the  probable  reason  for  semi- 
circular canals,  the  cochlea  and  their  appendages. 


200 


ANATOMICAL  CLASS  BOOK. 


MUSICAL  EAR. 

No  question  oftener  arises,  on  surveying  the  auditory 
apparatus,  than  this,  viz.  — why  has  one  person  an  ear  for 
music,  when  another,  whose  internal  organ  is  as  beauti- 
fully and  nicely  constructed,  is  totally  unable  to  appreciate 
harmonious  sounds  ? The  difficulty,  probably  is  in  the 
peculiar  development  of  some  portion  of  the  brain,  and 
therefore  does  not  arise  in  consequence  of  a defect  in  the 
original  conformation  of  the  ear.  It  obviously  requires 
as  delicate  auricular  perception  to  appreciate,  and  imitate 
articulate  sounds,  as  it  does  to  sing  in  concert.  It  is  by 
no  means  uncommon  for  an  individual  to  cultivate  the 
highest  departments  of  instrumental  music,  and  at  the 
same  time  be  wholly  unable  to  sing.  This  is  entirely 
owing  to  some  defect  of  the  vocal  organs.  A perfect  or- 
ganization of  both,  in  the  same  individual,  united  to  that 
inscrutable  condition  of  the  brain  which  gives  the  taste 
for  music,  constitutes  the  most  gifted  performer,  and  such 
as  Handel,  Mozart,  Beethoven,  Mad.  Catalina,  Garcia,  the 
wonderful  Paganini,  and  a few  others,  have  exhibited  to 
the  highest  degree  of  human  perfection. 

Another  circumstance  in  relation  to  the  musical  ear,  is 
the  following:  some  persons  have  the  ear  as  well  as  the 
taste  for  music,  and  yet  find  it  impossible  to  accompany 
others  in  a performance.  This  arises,  probably,  in  most 
cases,  in  consequence  of  a non-agreement  in  the  tension 
of  the  drum-heads  of  the  two  ears,  or  a want  of  corres- 
pondence in  the  calibre  of  the  internal  tubes  ; hence  one 
ear  perceives  sounds  (o  be  half  a tone  above  or  below  the 
other  : — the  same  occurs  in  respect  to  the  focal  distance, 
oftentimes,  of  the  eyes.  Time  rarely  corrects  the  former, 
though  in  the  latter  it  finally  modifies  the  aberration.* 

*Philosophers  of  antiquity  were  more  conversant  with  the  rloctrine 
of  sounds,  than  the  moderns  : the  remarkable  cavern,  hewn  in  a solid 


ANATOMICAL  CLASS  BOOK. 


201 


DISEASES  OF  THE  EARS. 

A ringing  in  the  ear  is  an  indication  of  a diseased  state 
of  the  nerve ; generally,  it  arises  from  some  slight  in- 
flammation. The  beating  of  adjacent  arteries,  in  conse- 
quence of  inflammation  in  the  throat,  may  excite  the  nerve, 
which  being  incapable  of  transmitting  any  sensation  but 
that  of  sound,  the  ringing  is  an  imperfect  sensation.  The 
eye,  when  the  optic  nerve  is  encroached  upon  by  inflam- 
mation of  surrounding  parts,  or  the  pressure  of  a growing 
tumor,  transmits  the  sensation  of  light,  though  the  indi- 
vidual be  in  total  darkness;  affections  of  the  brain  itself 
may  remotely  excite  a morbid  action  in  many  or  all  the 
nerves  of  sense.  Hence,  persons  dying  of  acute  inflam- 
matory diseases,  complain  of  hearing  loud  and  strange 
noises,  although  the  apartment  is  perfectly  still. 

EAR-ACHE. 

Very  many  individuals  are  subject  to  excruciating  pain 
of  the  internal  ear,  on  taking  the  slightest  cold,  or  from 
exposing  themselves  to  a humid  atmosphere;  and  others 
seem  to  inherit  the  disease,  which  no  application  can  re- 
move. A peculiar  irritability  of  the  nerve  that  crosses 
the  drum-head,  (corda  tympani)  may  be  one  cause,  — the 
vascular  covering  of  which,  suffering  from  a chronic  in- 
flammation, compresses  the  nerve  and  thus  produces  al- 
most intolerable  agony.  Defending  the  external  opening 
with  cotton  wool,  or  lint,  is  a common  and  rational  de- 
fence ; but  the  introduction  of  oils,  spirits  and  the  like,  is 
often  attended  with  pernicious  consequences.  Generally 

rock  by  a celebrated  tyrant,  and  called  Dionysius'  ear , is  said  to  have 
been  an  exact  model  of  the  windings  of  the  human  ear.  Vitruvius 
gives  an  interesting  account  of  the  manner  in  which  the  Greeks  con- 
trived to  augment  the  compass  of  the  voice  in  theatres,  by  placing 
large  metal  vases  in  different  parts  of  those  edifices. 


202 


ANATOMICAL  CLASS  BOOK. 


such  cases  end  in  deafness.  Nature,  to  save  the  rest  of 
the  machine  from  becoming  disordered,  by  its  sympathy 
with  the  diseased  member,  finally  destroys  it,  as  firemen 
demolish  contiguous  buidings,  to  save  a town,  when  they 
can  no  longer  master  a threatening  conflagration.* 

PARTIAL  DEAFNESS,  FROM  A COLD. 

Probably,  in  a majority  of  cases,  partial  deafness  arises 
from  a slight  inflammation  of  the  tube  opening  behind  the 
palate.  In  consequence  of  this,  the  balance  between  the 
air  in  the  tympanum  and  mouth,  is  destroyed,  and  the  reg- 
ular vibratory  function  of  the  membrane  is  altered.  A 
deafness  in  one  ear  generally  depends  on  this  cause. 
Deafness  in  fevers  is  an  excellent  symptom,  and  offers  en- 
couragement in  the  worst  cases,  because  it  is  an  evidence 
of  a diminution  of  the  morbid  condition  of  the  brain. 

PERMANENT  DEAFNESS. 

A total  deafness  implies  a destruction  of  the  organ  : 
but  we  apprehend  there  are  only  a very  few  persons  in  this 
condition.  Even  in  those  unfortunate  fellow-beings  who 
are  deaf  and  dumb , the  faculty  of  hearing,  to  a certain  ex- 
tent, still  exists.  They  hear  the  report  of  a cannon,  or 
heavy  thunder,  which  act  so  powerfully  on  the  body  as  to 

* Painful  affections  of  the  ear  may  be  induced  from  habitually  pick- 
ing the  ears,  — a very  pernicious  practice.  In  India,  where  a class  of 
men  follow  the  profession  of  cleansing  ears,  cutting  the  nails,  &e  — 
Ihough  in  that  climate  the  secretions  may  be  fluid,  in  greater  abund- 
ance, and  discharge  freely,  the  plucking  of  the  hairs  and  frequent 
introduction  of  scraping  instruments  render  the  organ  irritable,  and 
less  accurate  in  the  perception  of  sounds. 

Tumors,  ulcerations  and  other  troubleome  complaints  are  brought 
on  by  picking  them.  A sudden  pressure  on  the  corda  tympani, 
a nerve  belonging  to  the  face,  which  crosses  the  drum  head,  by  the 
head  of  a pin,  may  forever  after  render  it  liable  to  inflame  on  the 
slightest  exposure. 

Fluids  ought  not  to  be  poured  into  the  external  ear  to  drown  in- 
sects, as  the  worst  consequences  may  ensue. 


ANATOMICAL  CLASS  BOOK. 


203 


rouse  the  sleeping  energies  of  the  nerve.  In  fact,  the  tre- 
mor is  communicated  through  the  bones  of  the  head. 
Fishes,  of  the  bony  kind,  have  the  organ  of  hearing  acted 
upon  in  the  same  manner,  as  the  nerve  is  completely  cased 
up  in  solid  bone,  without  either  drum-head  or  external 
openings. 

CONCLUSION. 

None  of  the  organs  of  sense  are  more  complicated  or 
splendidly  constructed  than  the  one  under  consideration. 
The  will  has  it  but  slightly  under  its  control,  and  being 
unable  ‘ to  withdraw  itself  from  impressions,’  it  has  the 
curious  apparatus  of  little  bones  to  increase  or  diminish 
the  intensity  of  impressions,  like  a regulator  between  the 
external  agent  and  the  nervous  cords.  Judgment,  by  the 
combined  assistance  of  the  other  senses,  perfects  the 
function  of  the  organ  — and  ideas,  without  number,  are 
constantly  ushered  into  being  by  the  sense  of  hearing. 

By  this  sense,  music  is  a never  failing  source  of  plea- 
sure, heightened  and  infinitely  modified,  according  to  the 
physical  development  of  the  ear,  and  the  discipline  and 
education  to  which  it  has  in  modern  times  been  subjected. 
The  causes  of  the  pleasure  resulting  from  harmony  and 
melody,  are  very  far  from  being  satisfactorily  explained, 
notwithstanding  the  sagacious  conjectures  and  repeated 
attempts  of  the  most  able  metaphysicians,  as  well  as  phy- 
siologists : we  know  no  more  of  them  than  we  do  of  the 
causes  of  the  pleasures  and  pains  of  all  the  other  senses. 


204 


ANATOMICAL  CLASS  BOOK. 


QUESTIONS. 


Of  what  use  is  the  external  ear  ? 

What  is  the  tympanum  ? 

How  many  bones  are  found  in  the  internal  ear  ? 

What  is  the  use  of  the  drum? 

Is  there  any  communication  between  the  mouth  and  inter- 
nal ear  ? 

What  is  the  vestibule  ? 

What  do  you  understand  by  the  cochlea  ? 

Is  there  a fluid  in  the  vestibule  ? 

What  is  the  fenestra  ovalis  ? 

Where  is  the  acoustic  nerve  placed  ? 

What  is  the  use  of  the  little  bones  ? 

Can  sound  be  heard  without  the  stapes  ? 

What  are  the  semicircular  canals  for? 

Does  a rupture  of  the  drum  destroy  the  sense  of  hearing  ? 
Of  what  use  is  air  in  the  tympanum? 

What  constitutes  a musical  ear  ? 

What  produces  permanent  deafness? 

Of  what  use  are  cells  in  the  bone,  near  the  tympanum  ? 
Why  do  deaf  persons  hear  better  with  the  mouth  open  ? 
How  does  the  internal  ear  of  birds  differ  from  man’s  ? 

Can  a person  hear  without  the  external  ear  ? 

Why  is  pain  produced  by  touching  the  drum  ? 

What  is  the  use  of  ear  wax  ? 

Of  what  use  is  the  round  window  of  the  tympanum  ? 


ANATOMICAL  CLASS  BOOK. 


205 


THE  EYE. 

No  one  has  been  able  to  explain  how  or  ivhy  we  see. 
The  visual  organs  are  constructed  with  such  exact  refer- 
ence to  the  laws  of  light,  that  telescopes  and  microscopes, 
are  but  imitations  and  modifications  of  the  apparatus  of 
the  human  eye.  There  is  a difference,  however,  between 
the  animate  and  inanimate,  the  most  wonderful  and  as- 
tonishing. The  first  is  a perceiving  instrument;  the 
second,  a receiving. 

All  animals  living  on  land,  have  their  eyes  very  similar 
in  structure. 

In  carnivorous  animals,  the  original  principle  of  vision 
is  preserved,  but  most  curiously  modified,  according  to 
their  habits  and  characters. 

Those  that  live  by  violence,  have  the  power  of  seeing 
in  the  dark. 

Fishes,  by  a further  modification  of  the  original  appa- 
ratus, probably  see  distinctly  in  the  darkest  night. 

With  another  alteration,  not  unlike  changing  the  dis- 
tances between  the  lenses  of  a spy-glass,  another  family, 
as  seals,  &c,  see  alternately  in  two  elements.  Still  fur- 
ther, on  the  descending  scale  of  creation,  insects  are  pro- 
vided with  motionless  eyes,  — giving  them  the  faculty 
of  seeing  in  every  possible  direction.  And,  lastly,  in 
snails  and  some  kinds  of  worms,  the  eyes  are  fixed  at  the 
extremity  of  a moveable  feeler,  adapting  them  to  different 
focal  distances,  — or  they  can  be  drawn  entirely  within 
18 


206 


ANATOMICAL  CLASS  BOOK. 


the  head,  for  safe  keeping,  when  not  in  use,  precisely 
on  the  principle  of  care  that  we  draw  out  the  slides  of 
an  opera  glass,  and  close  them  up  again,  when  no  longer 
needed. 


THE  SOCKET  IN  WHICH  THE  EYE  ROLLS. 

Several  thin  pieces  of  bone  assist  in  the  formation  of  the 
orbit,  which,  in  a dry  skull,  is1  shaped  much  like  a pear, 
with  its  large  end  turned  outward.  The  upper  plate  of 
bone  is  arched,  having  the  brain  resting  on  it  above,  and 
the  eye-ball  moving  under  it  below.  Externally,  the  eyes 
are  at  considerable  distance,  but  the  inner  termination  of 
the  orbits,  answering  to  the  small  end  of  the  fruit,  are 
quite  near  together.  At  their  points  is  a ragged  hole, 
in  each,  through  which  the  nerve  of  vision  enters  the 
brain.  A large  quantity  of  fat  is  deposited  in  these 
sockets,  between  the  bones  and  eye-ball,  that  the  latter 
may  always  move  with  perfect  freedom,  and  without  fric- 
tion, in  all  directions.  After  a long  sickness,  the  cushion 
of  fat  is  absorbed  with  that  deposited  in  the  bones,  to  sus- 
tain the  system,  which  accounts  for  the  sinking  in  of  the 
eye  : as  the  person  recovers,  the  stomach  resumes  the  task 
of  taking  care  of  the  body,  the  fat  is  deposited  again,  and 
the  eye  becomes  prominent  as  before. 

GLOBE  OF  THE  EYE. 

When  detached  from  the  surrounding  parts,  the  eye- 
ball does  not  appear  exactly  round  : it  is,  in  outline,  more 
than  two  thirds  of  a large  sphere,  with  a portion  of  a lesser 
globe  laid  upon  it. 

The  use  of  this  arrangement  is  obvious.  If  the  ball 
had  been  actually  round,  the  compass  of  vision  would 
have  been  very  limited  : as  it  is,  the  smaller  portion,  by 
its  short  curve,  protrudes  so  far  beyond  the  socket,  where 


ANATOMICAL  CLASS  BOOK.  207 

the  globe  is  lodged  for  safety,  that  the  sphere  of  vision  is 
very  much  enlarged. 

MUSCLES  OF  TIIE  EVE. 

To  move  the  ball,  muscles  -were  necessary  ; otherwise, 
animals  would  be  obliged  to  turn  their  bodies  as  often  as 
an  object  was  to  be  seen.  Of  these,  four  are  straight, 
going  from  the  sides  of  the  ball,  to  be  fastened  near  the 
hole,  at  the  termination  of  the  bony  cavity  : their  office 
is  to  hold  the  eye  firmly,  in  a fixed  position,  as  in  steadily 
contemplating  a painting.  Two  others  are  given,  making 
six  in  the  whole,  to  express,  principally,  the  passions  of 
the  mind  : they  are  denominated  the  oblique,  in  conse- 
quence of  their  oblique  movement  of  the  eye.  One  rolls 
it  upward  and  inward,  as  in  viewing  a button,  midway  on 
the  forehead  ; the  other,  going  through  a loop,  is  so  purely 
mechanical,  that  it  has  been  the  theme  of  admiration  with 
philosophers  in  all  ages,  carries  the  eye  downward  and  out- 
ward. The  last  action  may  be  shown  by  looking  at  a but- 
ton, laid  on  the  shoulder.  Although  these  oblique  muscles 
exist  in  monkeys  and  nearly  all  tribes  of  quadrupeds,  they  are 
imperfectly  developed  ; showing  most  conclusively  that 
they  were  designed  for  expressing  the  feelings  and  passions 
of  man  — an  ineffable  language,  which  all  the  brute 
creation  have  the  sagacity  to  understand.  When  one  of 
the  four  straight  muscles  is  shorter  than  its  fellow  on  the 
opposite  side,  it  produces  the  cross-eye  or  squinting. 


208  ANATOMICAL  CLASS  BOOK. 


Explanation  of  Figure  80. 

This  plan  exhibits  the  muscles,  viewed  obliquely  from  the  upper 
and  outer  side  of  the  right  eye. 

a.  The  eye-ball. 

b.  Part  of  the  upper  eye-lid. 

c.  Tunica  Conjunctiva,  or  continuation  of  the  common  skin  of  the 
forehead,  which  turns  over  the  edges  of’  the  lids,  and  is  finally  car- 
ried over  the  front  of  the  globe,  but  perfectly  transparent  at  this 
point. 

d.  The  integuments  of  the  right  side  of  the  nose. 

e e.  The  optic  nerve. 

f.  The  four  straight  muscles,  with  the  levator  or  raising  muscle 
of  the  upper  eye-lid,  together  with  the  superior  oblique  muscle  em- 
bracing the  optic  nerve  where  it  enters  the  orbit. 

g.  The  levator  of  the  lid  drawn  aside. 

h.  Levator  occuli,  or  superior  straight  muscle,  — to  roll  the  ball 
upward 

i.  Abductor  occuli,  rolls  the  ball  outward. 

k.  Adductor  occuli,  rolls  it  towards  the  nose. 

l.  Depressor  occuli,  rolls  the  ball  downward,  towards  the  cheek. 

m.  The  superior  oblique  muscle,  passing  through  the  loop  at  n. 

n.  Called  the  trochlea , or  pulley,  but,  in  fact,  a simple  loop. 

<>.  Insertion  of  the  superior  oblique  muscle  in  the  eye-ball. 

p.  The  inferior  oblique  muscle,  taking  its  rise  from  a bone. 

q.  The  insertion  of  the  tendon  of  the  inferior  oblique  muscle  in 
the  first  coat  of  the  ball. 


ANATOMICAL  CLASS  BOOK. 


209 


COATS  OF  THE  EYE. 


Such  is  the  mechanical  arrangement  of  the  different 
coats  or  coverings  of  the  eye,  answering  in  use,  to  the 
brass  tubes  of  a spy-glass,  that  one  is  fitted  within  the 
other,  like  a nest  of  boxes  : they  are  three  in  number. 

Fig.  81. 

Explanation  of  Figure  81. 

This  is  a plan  of  the  coats,  or  as 
they  are  sometimes  termed,  tunics. 

Reference  should  be  made  to  this 
after  reading  the  text.  The  natural 
figure  of  the  eye,  in  outline,  is  pre- 
served. 

a.  The  Sclerotic,  or  first,  hard 
tunic . 

? q b.  The  Choroid,  or  fleecy  tunic, 

c.  The  Retina,  or  third  and  in- 
most tunic,  which  is  an  expansion  of 
the  optic  nerve  g — the  certain  seat 

of  vision. 

d.  The  Cornea,  or  prominent,  transparent  circle,  over  which  the 
lids  close,  in  winking. 

e.  The  Crystaline  lens,  or  little  magnifying  glass  of  the  eye, 
about  a quarter  of  an  inch  in  diameter. 

f.  Is  the  space  filled  by  one  of  the  fluids  of  the  eye,  and  called 
the  anterior  chamber. 

g.  The  stump  of  the  optic  nerve,  which  is  prolonged  into  the 
substance  of  the  brain. 


1st.  The  first  is  the  Sclerotic*  coat,  thick,  firm,  and 
possessing  but  little  sensibility.  Its  hardness  gives  secu- 
rity to  the  delicate  membranes  beyond  ; affords  attach- 
ment for  the  muscles ; and  by  its  elasticity,  equally  distends 
the  ball,  that  none  of  the  humors  may  suffer  from  pres- 
sure. Happily  the  hard  coat  is  very  rarely  diseased. 
Fishes  have  a sclerotic  coat  strictly  hard,  being  either 
cartilaginous  or  firm  bone,  graduated  in  this  respect  ac- 
cording to  the  depth  to  which  they  descend  in  search 
of  food.  Through  this  coat,  in  what  is  called  the  white 


* Sclerotic,  from  a Greek  word  meaning  hard. 

18* 


210 


ANATOMICAL  CLASS  BOOK. 


of  the  eye,  the  occulist  plunges  a needle  to  cure  some 
kinds  of  blindness. 

2d.  Choroid*  is  the  name  of  the  second  coat,  having 
a dark  red  color,  and  apparently  slightly  connected  with 
the  first.  By  carefully  cutting  oft’  the  sclerotic  from  a 
bullock’s  eye,  with  scissors,  the  choroid  will  be  beautifully 
exhibited,  sustaining  the  humors.  Minute  dissection, 
under  a microscope,  shows  that  this  tunic  is  a complete 
web  of  arteries  and  veins;  — hence  its  reddish  hue.  Be- 
tween this  and  the  sclerotic,  fine  silvery  threads  are  seen, 
which  hold  a control  over  the  Iris,  yet  to  be  described,  — 
determining  by  their  influence  how  much- or  how  little 
light  may  safely  be  admitted  into  the  eye.  The  inside  of 
this  membrane  resembles  closely  woven  wailed  cloth,  hav- 
ing a fleecy  nap,  similar  to  velvet,  called  Tapetum! 
This  tapetum  is  particularly  interesting  in  a philosophical 
point  of  view,  as  on  its  shade  of  color,  in  a great  measure, 
as  will  be  more  fully  explained  in  the  sequel,  depends  the 
power  of  seeing  in  the  dark. 

3d.  Retina, \ so  called  from  its  resemblance  to  a net, 
completes  the  number,  being  the  innermost  and  last.  Its 
color  is  that  of  gum  arabic,  or  ground  glass : nothing  can 
be  more  delicate,  being  too  tender  to  bear  its  own  weight. 
In  fact,  it  is  the  expansion  of  the  optic  nerve,  the  imme- 
diate seat  of  vision.  To  see  it  well,  an  eye  should  be 
taken  to  pieces  in  a tumbler  of  water, 

* Choroides,  — like  a lamb-skin,  fleecy. 

) Tapetum — resembling  cloth,  called  tapestry, 
tfietina,  — a net. 


ANATOMICAL  CLASS  BOOK 


211 


Fig.  82. 


Explanation  of  Figure  82. 
from  dissection  of  a human  eye,  the 
organ  being  represented  of  the  pro- 
per size. 

a.  The  optic  nerve, 
h b.  The  Sclerotic  coat  cut  and 
turned  outward. 

c.  A circular  portion  of  the  Scle- 
rotica, being  a rim  of  the  white  of 
the  eye,  cut,  and  turned  upward, 
having  in  its  embrace  the  cornea. 

d.  The  cornea. 

ee.  One  half  the  Iris,  in  its  place, 
the  other  half  being  removed. 
f.  The  Pupil,  soon  to  be  descri- 
bed, with  the  crystalline  lens  in  its  place. 

g.  The  Ciliary  circle,  or  second  vertical  partition,  within  the 
eye,  behind  the  iris. 

h h.  Choroid  coat. 

i.  The  Ciliary  processes,  or  ruffle-like  plaits  of  the  ciliary  circle, 
yet  to  be  explained.  A small  portion  of  the  iris  is  cut  away  to  show 
them. 

k.  A portion  of  the  iris  cut  and  turned  back. 

l.  The  floating  points  of  the  ciliary  processes,  also  turned  back. 

m.  The  middle  smooth  part  of  the  retina,  seen  by  cutting  a hole 
through  the  choroid  coat. 

n.  The  roots  of  the  ciliary  processes,  to  which  the  black  paint, 
secreted  by  the  tapetum  or  inner  surface  of  the  choroides,  adheres. 

o.  The  ciliary  processes  inserted  into  the  sac  which  contains  the 
cry st aline  lens. 


THE  CORNEA. 


Anteriorly,  that  clear,  shining  wall,  resembling  a watch 
crystal,  which  famishes  the  membraneous  box,  is  called 
the  cornea.  Simple  as  this  thin  crystal  appears,  it  is 
infinitely  curious  in  structure.  It  is  made  of  thin  pellu- 
cid plates,  one  over  another,  held  together  by  a spongy 
elastic  substance.  By  maceration  in  water  a few  hours, 
the  sponge  will  absorb  it  to  such  a degree,  that  the  plates 
may  be  distinctly  felt  to  slide  upon  each  other,  between 
the  thumb  and  finger. 

Little  glands,  like  bags  of  oil,  only  to  be  seen  by  the 
most  powerful  microscope,  are  lodged  under  the  first 
plate,  which  are  continually  oozing  out  their  contents 


212 


ANATOMICAL  CLASS  BOOK. 


upon  the  surface,  which  gives  the  sparkling  brilliancy  to 
this  part  of  the  eye.  As  death  approaches,  this  fluid 
forms  a pellicle,  like  a dark  cloud,  over  the  lower  portion 
of  the  cornea.  This  formation  is  taken  to  be  a sure  indi- 
cation of  approaching  dissolution.  See  fig.  81,  letter  d, 
and  fig.  82,  letters  c and  d,  for  representation  of  the  cornea. 

mts. 

By  looking  into  a person’s  eye,  there  seems  to  be  a ver- 
tical partition,  either  black,  blue,  or  hazle,  as  the  case 
may  be,  which  prevents  us  from  looking  into  the  regions 
beyond,  — having  a round  hole  in  its  centre.  This  is  the 
iris,  while  its  central  orifice  is  denominated  the  pupil. 
How  the  diameter  of  this  hole  is  enlarged  or  diminished, 
has  never  been  explained  satisfactorily.  One  fact,  how- 
ever, is  certain,  that  the  pupil  is  large  or  small,  according 
to  the  quantity  of  light  that  may  be  necessary  to  the  for- 
mation of  a distinct  picture  of  the  object  seen.  — and  this 
change  is  effected  without  our  being  conscious  of  the 
action. 

From  the  reflection  of  such  rays  as  are  not  admitted 
through  the  pupil,  or  central  hole,  we  account  for  much 
of  the  lively  brilliancy  of  the  iris.  On  its  back  side  it  is 
rather  fleecy.  Over  this  is  spread  a black,  blue,  hazle,  or 
tea-colored  paint,  which  gives  a permanent  color  to  the 
eye.  It  has  been  remarked,  that  the  eyes  and  hair  ordi- 
narily correspond  in  color.  Whenever  the  iris  acts,  as,  for 
instance,  it  does  in  going  from  a dark  into  a light  room, 
the  pupil  is  made  smaller,  — acting  uniformly  in  its  fibres, 
to  keep  it  circular.  On  returning  to  the  dark  apartment, 
the  pupil  enlarges  again.  A knowledge  of  this  fact,  will 
explain  the  reason  of  a painful  sensation  in  the  eye,  caus- 
ed by  a strong  and  sudden  light.  As  soon  as  the  iris  has 
had  time  to  diminish  the  size  of  its  pupil,  we  can  endure 


ANATOMICAL.  CLASS  BOOK. 


213 


the  same  luminous  object  with  perfect  comfort.  When 
we  leave  a well-lighted  room,  on  first  going  into  a dark 
street,  everything  appears  lurid  and  indistinct.  The  iris 
soon  begins  to  enlarge  the  pupil,  to  admit  more  light,  and 
when  that  has  been  accomplished,  although  in  compaia- 
tive  darkness,  we  recognise  objects  without  an  effort. 
Acting  independently  of  the  will,  its  duties  are  like  those 
of  a faithful  sentinel,  always  consulting  the  safety  of  the 
splendid  optical  instrument  confided  to  its  care,  with  re- 
ference to  its  subserviency  to  the  being  for  whose  use  it 
was  exclusively  constructed.  Were  it  otherwise,  — were 
it  left  to  our  own  care,  how  often  it  would  be  neglected, 
and  indeed,  totally  ruined,  solely  for  the  want  of  undivided 
attention. 

Parrots  have  a voluntary  control  over  the  pupil,  opening 
and  closing  it  at  pleasure.  How  this  is  done,  or  why,  in 
the  constitution  of  that  bird,  it  is  necessary,  we  cannot 
determine.  Cats,  also,  appear  to  have  a similar  power  of 
graduating  the  quantity  of  light,  admitted  into  their  eyes, 
as  it  suits  their  own  convenience. 

In  carnivorous  quadrupeds,  the  pupil  is  commonly  oval 
and  oblique,  permitting  them  to  look  from  the  bottom  to 
the  top  of  a tree  without  much  elevation  of  the  head. 
Gramnivorous  quadrupeds  have  an  oblong  pupil,  placed 
horizontally,  with  respect  to  the  natural  position  of  the 
body.  This  form  gives  them  the  faculty  of  surveying  the 
expanse  of  a field,  at  once.  See  fig.  82,  letters  e e , and  k. 
Fig.  83,  letters  c c. 

CILIARY  PROCESSES. 

Directly  behind  the  iris,  is  a second  curtain,  having  a 
central  hole  through  it,  corresponding  with  that  through 
the  first  curtain,  but  nearly  as  large  as  the  whole  diameter 
of  the  lens.  All  the  luminous  rays  which  are  converged 
by  the  convexity  of  the  cornea,  which  is,  in  effect,  a piano 


214 


ANATOMICAL  CLASS  BOOK. 


convex  lease,  cannot  enter  through  the  pupil ; many  of 
them  strike  the  plane  of  the  iris,  and  are  reflected  back, 
as  on  a looking-glass,  without  penetrating  its  substance. 
If  any  rays  were  to  get  through,  by  such  an  irregular  pro- 
cess, it  would  produce  great  confusion,  by  destroying  the 
outline  and  vividness  of  the  image  previously  made  on  the 
retina,  through  the  natural  opening.  To  prevent  such 
mishaps,  the  paint  on  the  back  of  the  iris  is  to  absorb  such 
rays  as  are  not  reflected,  and  have  a tendency  therefore  to 
pass  onward.  Nature,  as  though  fearful  that  circumstan- 
ces might  so  alter  the  condition  of  the  pigment,*  as  that 
some  light,  notwithstanding  this  precaution',  might  pene- 
trate, has  interposed  this  second  yeil,  — solely  it  is  sup- 
posed to  stop  all  wandering  rays. 

This  ciliary  curtain  presents  three  thicknesses,  and 
lastly,  has  a thick  coat  of  black  paint  on  its  back.  In  or- 
der to  give  it  treble  security,  as  it  regards  thickness,  it  is 
plaited  like  the  folds  of  a ruffle.  There  are  seventy  folds 
in  the  human  eye,  of  equal  width,  nicely  laid,  one  over 
the  other.  A part  so  highly  important,  cannot  be  over 
looked  in  studying  the  philosophy  of  vision. 

* Pigment,  — paint, 


ANATOMICAL  CLASS  BOOK. 


215 


Fig.  83. 


Explanation  of  Fig.  S3. 

This  plan  presents  a longitudinal  section  of  the  left  eye  and  orbit. 

a.  The  upper  eye-lid,  shut. 

b.  The  cornea. 

cc.  The  cut  edges  of  the  iris. 

d.  The  pupil  or  round  hole  through  the  centre  of  the  iris. 
which,  in  the  living  eye,  resembles  a black,  highly  polished  dot. 

ee.  The  cut  edges  of  the  sclerotic  and  choroid  tunics,  with  the 
retina,  before  exhibited  in  the  preceding  drawings 

f.  The  crystaline  lens,  as  it  is  lodged,  with  reference  to  other 
parts. 

gg.  The  Ciliary  processes  continued  from  the  choroid  coat.  The 
plaits  are  here  distinctly  seen. 

h.  The  optic  nerve  running  from  the  brain,  through  the  bones, 
to  the  globe  of  the  eye,  apparently  closely  embraced  by  the  straight 
muscles. 

i.  The  levator  muscle  that  raises  the  upper  eye-lid. 

k.  The  upper  straight  muscle  of  the  eye. 

l.  Inferior  straight  muscle,  its  antagonist,  on  the  under  side  of 
the  ball,  called  depressor  occuli. 

m.  A section  of  the  inferior  oblique  muscle,  used  in  rolling  the 
eye  upward  and  inward,  as  in  looking  at  a button  laid  above  the  root 
of  the  nose.  The  superior  oblique,  passing  through  a loop,  carries 
the  eye  downward  and  outward,  as  in  looking  at  the  top  of  the 
shoulder.  These  two  muscles,  by  old  writers,  were  termed  rotato- 
res  and  amatores,  in  allusion  to  their  office  of  rolling  the  ball  in  ex- 
pressing passions. 

nn.  A section  of  the  blood  vessels  and  nerves,  with  a large 
quantity  of  fat,  surrounding  the  optic  nerve. 


216 


ANATOMICAL  CLASS  BOOK. 


HUMORS  OF  THE  EYE. 

By  humors,  writers  mean  the  fluids  which  distend  the 
eye-ball.  They  are  three  in  number,  — possessing  differ- 
ent densities,  and  varying  much  in  quality,  quantity  and 
use.  Besides  fulfilling  the  first  intention,  — viz,  disten- 
sion,— they  are  so  purely  transparent,  as  to  offer  no  ob- 
struction to  the  free  passage  of  light.  Those  only  inter- 
ested in  this  description,  as  general  scholars,  by  close  ex- 
amination will  have  a perfect  idea  of  them,  and  will  con- 
sequently understand  the  real  nature  of  some  of  the  many 
causes  that  weaken  the  power  of  vision,  or  ultimately  pro- 
duce a total  blindness.  The  gratification  afforded  by  the 
examination  of  a bullock’s  eye,' — tracing  the  several  parts 
by  this  paper,  will  be  an  ample  compensation  for  the  labor, 
because  it  will  forever  fix  on  the  mind  interesting  facts, 
and  lead  the  reader,  insensibly,  to  a course  of  reflections, 
productive  of  much  intellectual  enjoyment. 

AQUEOUS  HUMOR.* 

The  aqueous  humor  is  the  first  in  the  order  of  demon- 
stration, lying  directly  back  of  the  cornea,  — so  clear, 
that  one  unacquainted  with  the  existence  of  it,  would  not 
suspect  a fluid  there.  In  volume,  it  is  far  less  than  the 
others  : it  keeps  the  cornea  prominent,  always  at  the  same 
distance  from  the  iris,  in  the  early  periods  of'life.  The 
space  occupied  by  the  aqueous  humor,  is  called  the  ante- 
rior chamber  of  the  eye.  (See  fig.  8!,  letter/-.)  Passing 
freely  through  the  pupil,  it  also  fills  an  exceedingly  thin 
apartment,  the  circumference  of  the  iris,  called  the  'pos- 
terior chamber.  Thus  it  will  be  comprehended  that  the 
iris,  or  in  familiar  language,  first  curtain,  is  actually  sus- 
pended and  floating  in  a liquor. 


Aqueous like  water. 


ANATOMICAL  CLASS  BOOK. 


217 


Were  it  not  for  such  a contrivance,  the  iris  would  soon 
become  dry  and  shrivelled,  by  the  intensity  of  the  sun, 
and  therefore  rendered  totally  unfit  to  perform  its  appro- 
priate office  of  opening  and  closing  the  pupil.  The  aque- 
ous humor  is  never  suffered  to  remain  long  at  a time,  but, 
on  the  contrary,  is  constantly  poured  in  and  again  drawn 
off  by  an  infinite  number  of  invisible  ducts.  By  being 
stationary,  it  would  become  speedily  turbid,  and  finally 
lose  its  transparency.  A knowledge  of  the  rapidity  of  the 
secretion  has  been  the  means  of  encouraging  occulists  to 
undertake  novel  methods  of  extracting  cataracts,  a kind 
of  dark  mote,  through  the  cornea,  as  the  most  certain  mode 
of  restoring  sight.  Twenty-four  hours  after  drawing  off 
the  aqueous  humor,  by  a puncture,  the  anterior  chamber 
will  be  full  again. 

Old  age,  characterized  by  a gradual  decay  in  the  vigor 
of  all  the  individual  organs,  shows  also  its  insidious  ap- 
proach in  the  eye.  Vessels  that  have  toiled  with  untiring 
diligence  to  the  meridian  of  life,  begin  to  show  a loss 
of  energy.  Those  which  have  carried  the  new,  pure 
liquid,  forward  a less  quantity  in  a given  time  than  for- 
merly,— while  those  whose  task  it  was  to  convey  away 
the  old  stock,  are  dilatory  in  the  performance  of  their 
work.  Hence,  from  being  kept  too  long  in  the  reservoir, 
in  consequence  of  a tendency  to  become  more  turbid,  it 
does  not  allow  the  light  to  pass  with  its  former  facility  to  the 
nerve  ; elderly  persons,  therefore,  have  indistinct  vision 
from  this  cause,  similar  to  looking  through  a smoky  at- 
mosphere. Fishes  have  no  aqueous  humor  at  all,  as  it 
could  be  of  no  service  in  the  element  in  which  they  swim 

Kept,  as  the  humor  is,  in  its  own  capsule,  it  gives  other 
advantages  to  the  apparatus  of  vision  : it  is  a concavo-con- 
vex glass,  absolutely  and  indispensably  requisite  in  an  in- 
strument that  will  produce  an  image  by  the  same  laws 
that  govern  the  eye.  A sensible  diminution  in  the  quantity 
19 


218 


ANATOMICAL  CLASS  BOOK. 


of  this  fluid,  is  very  apparent  in  people  advanced  in  years  : 
the  cornea  becomes  flatter;  thm  segment  of  it  is  so 
altered,  that  rays  of  light  are  no  longer  converged  as  in 
younger  days.  This,  together  with  corresponding  de- 
rangements within  the  globe,  constitutes  the  long-sighted- 
ness of  old  age,  — mechanically  overcome  by  wearing 
convex  spectacles.  So  gradually  are  the  changes  wrought 
by  age,  that  glasses  of  different  focal  distances  are  sought 
from  time  to  time,  to  keep  pace  with  the  progress  of 
decay. 

The  ingenuity  of  man  is  nowhere  more  curiously  dis- 
played, than  in  thus  availing  himself  of  his  discovery  of 
the  laws  of  refraction,  in  producing  artificial  lenses  to 
gratify  his  eye,  a never  failing  source  of  enjoyment,  long 
after  nature  has  begun  to  draw  the  blind  that  will  ulti- 
mately close  between  him  and  the  world  forever. 

CRYST  A LINE  LENS.* 

As  magnifying  glasses  of  different  refractive  powers 
give  perfection  to  optical  apparatus,  so  it  is  with  respect 
to  the  lenses  within  the  ball.  By  crystaline  lens , is  simply 
meant  a body  like  a button,  resembling  pure  flint  glass, 
somewhat  of  the  shape  of  a common  sun  glass,  convex,  on 
both  sides.  Its  posterior  convexity  is  greater  than  its 
anterior,  — thereby  bringing  the  rays  to  a point  a little  dis- 
tance behind  it.  Careful  investigation  shows  that  this 
lens  is  made  of  a series  of  plates,  applied  to  each  other 
like  the  coats  of  an  onion  : the  centre  is  firmer  tfyan  the 
edges. 

As.  a whole,  it  possesses  a highly  refractive  property,  but 
in  different  degrees,  according  to  the  thickness  of  the 
lens,  — receding  from  the  centre  to  the  circumference. 
Over  the  whole,  to  keep  it  from  sliding  in  any  direction, 

* Crystaline  lens,  — resembling  crystal  or  glass. 


ANATOMICAL  CLASS  BOOK. 


219 


that  the  centre  may  not  get  without  the  axis  of  vision, 
is  an  envelope,  having  connexion  with  all  the  coats,  where 
they  are  united  on  the  borders  of  the  cornea,  and  where 
it  joins  the  white  part  of  the  eye.  Being  equally  trans- 
parent with  the  lens  itself,  it  cannot  be  conveniently  ex- 
hibited. 

Cataracts,  the  most  frequent  cause  of  blindness,  origi- 
nate in  the  lens;  sometimes  half  way  between  the  centre 
and  margin,  hut  ordinarily  in  the  centre.  They  are  either 
a peculiar  deposition  of  opaque  or  milky  matter,  entirely 
preventing  the  ingress  of  light,  or  there  is  an  opacity  of 
some  of  the  internal  layers  of  plates,  equally  destructive  to 
vision.  Many  children  are  born  with  this  affection  ; and 
at  all  ages,  they  are  liable  to  form.  To  remove  cataracts 
by  extraction,  the  operator  slides  a sharp,  thin  knife,  re- 
sembling a lancet,  through  the  cornea,  from  one  side  to 
the  other,  cutting  one  half  from  its  natural  attachment — - 
leaving  it  in  the  form  of  a flap,  thus: 


Fig,  84.  - 


Explanation  of  Fig.  84. 

This  plan  represents  an  eye.,  surrounded  by-  its  natural  appen- 
dages, with  a Unite  passing  through  the  anterior  chamber.  A dotted 
line  indicates  the  lower  edge  of  the  flap,  made  by  cutting  off  just  one 
half  the  cornea  f on,  its  attachment  with  the  sclerotica,  in  order  to  al- 
low the  crystalina  lens  to  escape,  whenever  the  knife  is  withdrawn. 

As  a matter  of  course,  the  aqueous  humor  escapes  in  a 
twinkling,  at  the  same  moment,  the  capsule  of  the  lens, 
previously  ruptured,  designedly,  by  the  point  of  the  knife, 


220 


ANATOMICAL  CLASS  BOOK. 


as  it  slides  along,  acts  upon  the  lens  by  spontaneous  con- 
traction, and  protrudes  it  through  the  wound.  Undoubt- 
edly the  grasp  which  the  straight  muscles  have  on  the  ball, 
accelerates  its  escape 

Thus,  in  taking  away  the  obstruction  to  sight,  the  whole 
lens  is  extracted. 

To  couch,  an  operation  often  mentioned,  and  often  per- 
formed, is  to  thrust  a delicate  needle  through  the  white 
of  the  eye,  just  on  its  border,  till  the  point  reaches  the 
lens,  which  is  then  depressed  into  the  lower  part  of  the 
eye,  below  the  optic  axis,  so  that  light  may,  by  entering 
the  pupil,  arrive  at  the  nerve.  In  this  last  operation,  fears 
are  always  entertained,  that  the  lens  may  rise  again  to  its 
former  position,  rendering  a repetition  of  the  operation 
indispensable.  Secondary  cataracts  sometimes  form,  after 
couching  or  extraction,  and  arise  in  consequence  of  a thick- 
ening and  opacity  of  the  capsule,  which  is  left  behind. 
Such  cases  are  more  alarming  in  their  progress  than  a 
disease  of  the  lens,  as  no  surgeon  is  warranted  in  promis- 
ing even  a partial  relief.  If  he  attempted  to  tear  away 
the  membrane,  he  might  alto  rend  every  other  within  the 
globe. 

A few  facts  of  this  kind  which  have  a practical  bearing, 
more  or  less  interesting  to  every  person,  may  lead  to  cor- 
rect views  in  relation  to  some  of  the  diseases  which  are 
common  to  this  curious  organ. 


ANATOMICAL  CLASS  BOOK. 


221 


Fig.  85. 


E.  The  anterior  chamber  of 


Explanation  of  Figure  85. 

This  is  a scheme  showing  how 
a bad  operator,  by  introducing  the 
couching  needle  too  near  the  cor- 
nea, may  rupture  the  ciliary  pro- 
cesses, and  actually  divide  the 
lens  in  two  pieces  without  moving 
it  from  the  optic  axis. 

A.  The  vitreous  humor. 

B.  The  lens. 

CC  Ciliary  processes,  torn  by 
the  lower  part  of  the  needle, 
thereby  doing  great  violence  and 
a permanent  injury  to  the  organ. 

DD.  The  iris. 
e aqueous  humor. 


Fig.  86. 

Explanation  of  Fig.  86. 

This  figure  represents 
the  mode,  and,  in  fact, 
the  place  into  which  the 
couching  needle  is  intro- 
duced, in  the  operation 
of  couching. 

A.  The  pupil  is  seen 
through  the  transparent 
cornea. 

B.  The  iris. 

C.  The  needle,  with  the  handle  elevated  so  as  to  depress  the 
point. 

D.  The  lens  and  point  of  the  needle  in  outline  ; this  precisely 
represents  the  position  of  the  lens  after  couching. 

VITREOUS  HUMOR. 

Beyond  the  two  humors  we  have  been  describing,  is 
the  third,  differing  essentially  from  either  of  them.  In 
volume  it  far  exceeds  the  others,  — occupying  more  than 
two  thirds  of  the  whole  interior  of  the  ball.  Its  consist- 
ence is  that  of  the  white  of  an  egg,  but  kept  in  place  by 
its  own  capsule.  When  the  sac  is  punctured  with  a pin, 
it  flows  out  slowly  in  consequence  of  its  adhesiveness. 
Like  the  preceding  humors,  it  is  transparent,  allowing  the 
free  passage  of  light  through  its  substance,  and  also  pos- 
19* 


222 


ANATOMICAL  CLASS  BOOK. 


messes  the  additional  quality  of  allowing  the  rays  to  sepa- 
rate again,  as  they  leave  the  point  at  which  they  were 
converged  just  back  of  the  lens.  Observation  proves 
that  the  vitreous  humor  is  kept  in  place  by  being  lodged 
in  cells.  Perhaps  a piece  of  sponge  might  give  a tolerable 
idea  of  the  cellular  structure,  admitting  it  to  be  as  trans- 
parent as  the  water  which  it  absorbs.  On  its  fore  part  it 
has  a depression,  in  which  the  posterior  convexity  of  the 
lens  is  lodged,  — as  represented  in  this  diagram.  Concave, 
therefore,  in  front,  and  convex  behind,  gives  another  kind 
of  optical  glass,  known  as  the  meniscus,  — the  crescent, 
faintly  resembling  the  first  quarter  of  the  new  moon. 


Any  person  possessing  an  ordinary  share  of  curiosity, 
can  examine  the  optic  nerve , at  leisure,  in  slaughter 
houses,  fish  markets,  and  in  fowls.  In  the  human  eye, — 
or  rather  extending  from  the  globe  to  the  brain,  — the 
optic  nerve  is  very  much  like  a cotton  cord,  somewhat 
larger  titan  a wheat  straw,  of  a mealy  whiteness,  and  not 
far  from  three  quarters  of  an  inch  in  length.  Arising  from 
the  substance  of  the  brain,  it  traverses  the  bony  canal  till 
it  reaches  the  back  of  the  eye-ball  ; as  soon  as  it  arrives 
in  contact,  as  it  were,  it  is  suddenly  divided  into  innumer- 
able filaments,  which  wend  their  way  into  the  globe, 


Fig.  87. 


One  dotted  line  indicates,  in  this 
diagram,  the  aqueous  humor;  an- 
other the  iiis,  and  a third  the  lens, 
and  the  fourth  the  vitreous  humor. 
Let  it  be  remembered  that  all  the 
space  between  the  bad;  side  of  the 
lens  and  optic  nerve,  is  filled  com- 
pletely, with  the  glairy,  vitreous 
humor,  the  third  fluid,  and  inmost 
.of  the  eye. 


Explanation  of  Figure  87. 


OPTIC  NERVE. 


ANATOMICAL  CLASS  BOOK. 


223 


through  very  minute  holes.  From  a fanciful  resemblance 
to  a sieve,  this  spot  on  the  sclerotica,  is  called  the  cribriform 
plate.  When  the  threads  have  emerged  within,  they  as- 
sume another  form,  by  expanding  into  a web,  constituting 
the  third  or  inmost  box.  Some  believe  the  nerve  is  spread 
on  a thin,  unseen  membrane,  in  the  form  of  a highly  or- 
ganized nervous  paste.  Here,  on  this  pulp,  having  con- 
siderable range  of  surface,  is  the  sole  seat  of  vision.  A 
vulgar  opinion  presupposes  some  exceedingly  acute  nervous 
point,  — the  exquisite  place  of  vision.  Nothing,  however, 
is  more  absurd;  vision  includes  considerable  surface.  In 
the  centre  of  the  substance  of  the  nerve,  an  artery  pene- 
trates the  eye,  accompanying  the  filaments,  to  nourish  the 
humors.  When  the  cornea  has  been  cut  away,  and  the 
iris  detached,  this  vessel  may  be  distinguished,  of  a bright 
scarlet,  spreading  its  hair-like  branches  about,  like  the 
limbs  of  a tree.  The  nerves  which  give  sensation  to  the 
eye,  connecting  it  with  the  system,  may  be  noticed,  as 
previously  remarked,  lying  between  the  two  first  coats. 
The  optic  nerve  conveys  to  the  mind  the  sensation  of  the 
existence  of  things,  as  perceived  by  the  eye,  while  the 
commands  of  the  same  mind  are  conveyed  to  the  organ 
by  these  little  threads  of  nerves,  so  insignificant,  as  to  be 
often  overlooked  in  a dissection  made  purposely  for  them. 


224 


ANATOMICAL  CLASS  BOOK. 


Pig..  83. 


Explanation  of  Fig.  88. 

In  this  figure,  the  cornea  is  cut  away,  and  the  sclerotic  dissected 
back.  This  is  a beautiful  and  easily  accomplished  dissection.  In  a 
bullock’s  eye  all  these  delicate  nerves  can  be  readily  displayed.  A 
pair  of  sharp  pointed  scissors  and  a few  pins,  to  hold  parts  to  a board, 
are  the  proper  instruments.  In  schools,  ladies  could  display  the 
whole  of  this  beautiful  optical  apparatus. 

a.  The  optic  nerve. 

b.  The  sclerotic  coat  turned  back,  so  as  to  show  the  vessels  of 
the  choroid  coat. 

cc.  The  ciliary  nerves,  seen  piercing  the  sclerotic  coat,  and  pass- 
ing forward  to  be  distributed  to  the  iris.  The  iris,  so  highly- 
organized,  is  not  supplied  by  any  nervous  influence  from  the  optic, 
but  by  the  hair-like  nerves,  here  displayed,  creeping  to  its  margin 
between  the  two  exterior  coats. 

d.  A small  nerve  passing  from  the- same  source  to  the  same  ter- 
mination, but  giving  off  no  visible  branches. 

ee.  Two  vena,  vorticosa,  or  whirling  veins,  so  denominated,  be- 
cause they  seem  to  fall  into  shapes,  resembling  falling  jets  of  water; 
these  return  the  blood  from  the  eye,  sent  in  by  its  central  and  other 
arteries. 

f.  A point  of  the  sclerotic,  through  which  the  trunk  of  one  of  the 
vein3  has  passed. 

g.  A lesser  vein. 

It.  The  circular  point  of  union,  where  all  the  coats  of  the  eye, 
together  with  the  cornea  and  iris,  seem  to  be  glued  firmly  together. 

i.  The  iris. 


ANATOMICAL  CLASS  BOOK. 


225 


k.  The  str  aight  fibres  of  the  iris. 

l.  A circle  of  fibres  or  vessels,  which  divide  the  iris  into  the 
larger  circle  k — and  the  lesser  one  m. 

m.  This  letter  points  to  the  lesser  circle  of  the  iris. 

n.  The  fibres  of  the  lesser  circle. 

o.  The  pupil. 

P1GMENTUM  NIGRUM.* 

Lastly,  to  complete  the  internal  structure,  and  fit  it  for 
the  performance  of  its  destined  office,  the  inside  surface 
of  the  second  coat,  choroides,  is  thoroughly  painted  black. 
In  the  order  of  explanation,  this  paint  is  just  behind  the 
retina.  When  the  humors  have  been  taken  out,  the  pig- 
ment is  readily  examined.  The  use  of  it  is  very  obvious; 
viz.,  to  absorb  any  aberrating  or  unnecessary  rays  of  light, 
which  would  confuse  the  vision,  or  destroy  the  intensity 
of  the  impression  on  the  expanded  retina,  or  to  suffocate 
them  entirely. 

SKIN  OF  THE  EYE,  OR  TUNTCA  CONJUNCTIVA. 

Behind,  the  eye,  by  its  long  cord  of  optic  nerve,  seems 
to  rest  on  one  extremity  of  an  axle  : — in  front,  the  skin, 
passing  over  the  eye,  as  it  comes  down  from  the  forehead, 
to  join  the  cheek,  is  the  other. 

To  comprehend,  clearly,  the  manner  in  which  the  eye 
is  fastened,  before,  — observe  how  the  skin  turns  over  the 
edge  of  the  lid,  going  about  three  quarters  of  an  inch  back, 
striking  the  ball  to  which  it  is  made  fast,  then  folded  back 
upon  itself,  adhering  to  the  whole  anterior  surface  of  the 
cornea,  — dipping  down  and  finally  mounting  over  the 
margin  of  the  lower  lid,  and  ultimately  loosing  itself  on 
the  face.  As  we  cannot  recognise  this  on  a living  eye, 
it  will  at  once  lead  one  to  suppose  it  is  as  clear  as  glass, 
which  is  the  case.  Streaks  of  blood,  when  the  eye  is  in- 


Pigmentum  Nigrum  — black  paint . 


226 


ANAT0A1I0AL  CLASS  BOOK. 


flamed,  lie  covered  over  by  the  tunica  conjunctiva.  Now 
if  particles  of  sand,  or  other  irritating  substances  get  under 
either  eye-lid,  they  cannot  possibly  enter  but  little  way, 
before  reaching  the  duplication  of  this  transparent  skin  ; 
there  is  no  danger,  therefore  ; the  offending  matter  cannot 
get  so  far  between  the  socket  and  ball,  backward,  as  to 
abridge  the  free  motion  of  the  organ,  or  do  a permanent 
injury  to  the  parts.  This  partition,  or  doubling  over  of 
the  conjunctiva,  is  a curious  provision,  as  we  are  thereby 
enabled  to  reach  the  source  of  irritation. 

The  principle  of  introducing  eye-stones,  to  extract 
foreign  matter,  is  this,  and  not  owing  as  Vulgarly  sup. 
posed,  to  the  crawling  about  of  a smooth  piece  of  sulphate 
of  lime,  on  some  forty  or  fifty  feet.  The  stone  is  so  much 
larger  than  the  extraneous  body,  already  there,  that  it  ex- 
cites a proportionably  larger  quantity  of  tears,  to  wash  it 
away  : in  effect,  therefore,  we  submit  to  a greater  tempo- 
rary evil,  to  get  rid  of  a lesser  one. 

Serpents  annually  shed  their  skins,  which,  unaccount- 
able as  it  at  first  appears,  are  whole  over  the  eyes.  That 
thin  sheet,  so  very  clear  and  fine  in  texture,  is  the  con- 
junctiva, showing  its  origin, — •hence  a similar  origin 
may  safely  be  inferred  over  other  eyes.  Every  species  of 
animal  with  which  naturalists  are  conversant,  possess  this 
defensive  transparent  membrane. 

THIRD  EYE-LID,  OR  MEMBRANA  NICTITANS. 

A third  eye-lid  is  given  such  animals  as  are  destitute 
of  hands,  or  are  incapacitated,  by  the  arrangement  of  their 
limbs,  from  reaching  their  eyes.  This  is  called  mem- 
brana  nictitans, — and  a more  striking  piece  of  mechan- 
ism there  is  not  in  existence.  It  slides  from  one  angle 
of  the  eye  to  the  opposite  one,  under  the  first  pair  of  lids, 
— and  that,  too,  whether  the  others  are  open  or  shut, 


ANATOMICAL  CLASS  BOOK. 


227 


being  totally  independent  of  them  in  muscular  action. 
Its  use  cannot  be  mistaken  : it  is  on  purpose  for  clearing 
away  matter  that  may  be  irritating  to  the  eye.  Any  ex- 
traneous substance  is  brushed  from  the  cornea  in  an 
instant,  by  the  broad  sweep  of  the  night  lid.  Birds  that 
seek  their  food  in  the  night,  as  owls,  defend  their  irrita- 
ble organs,  through  the  glare  of  daylight,  by  drawing  over 
this  singular  curtain.  Dogs,  cats,  foxes,  wolves,  bears, 
lions,  tigers,  &c,  can  each  of  them,  by  this  brush,  re- 
move the  minutest  mote  from  the  cornea,  more  expedi- 
tiously than  any  occulist  on  the  globe. 

TEARS. 

Perfection  is  everywhere  observed  in  animal  mechan- 
ics. The  eye  would  soon  become  a useless  instrument 
notwithstanding  the  nice  adjustment  of  its  several  parts, 
were  it  not  for  the  external  apparatus  of  eye-lids,  glands 
and  tears,  whose  combined  action  keeps  it  always  in  a 
condition  to  be  useful.  Were  not  the  cornea  frequently 
moistened,  it  would  become  dry  and  shrivelled.  To  ob- 
viate this,  a sack  of  fluid  is  fixed  just  under  the  edge  of 
the  orbit,  above  the  eye-ball,  which  is  continually  pouring 
out  its  contents  by  the  pressure  and  rolling  of  the  eye. 
Flowing  through  numberless  apertures,  it  washes  the 
crystal  and  finally  passing  into  grooves,  on  the  inner 
margin  of  both  eye-lids,  runs  to  their  terminations  in  a 
small  pin-like  orifice,  at  the  inner  angle.  To  keep  them 
open,  a hoop  is  set  in  the  mouth  of  this  tear  tube.  This, 
too,  can  be  shown  by  turning,  the  lid  outward  by  the 
finger.  Finally,  the  tears  are  conveyed  into  the  nose 
through  a bony  tube,  answering  the  double  purpose  of 
keeping  moist  the  lining  membrane,  on  which  the  sense 
of  smell  depends.  On  both  eye-lids,  at  the  roots  of  the 
eye-lashes,  are  in  each,  a row  of  glands,  equivalent  to 


228 


ANATOMICAL  CLASS  BOOK. 


bags,  smaller  than  pin  heads,  which  ooze  out  an  oily 
secretion,  to  prevent  the  adhesion  of  them  together,  as  is 
sometimes  the  case  when  the  eyes  are  much  inflamed. 
Surely  such  manifest  provision  for  contingencies,  is  another 
beautiful  illustration  of  super-human  contrivance. 


Fig.  89. 


Explanation  of  Fig.  89. 
This  plan  exhibits  the  natural 
size  of  the  passages  of  the  tears. 

a Is  the  lachrymal  gland,  or 
organ  that  secretes  the  tears; 
showing  its  natural  situation, 
with  respect  to  the  eye-  litis. 
bb.  The  eyelids  widely  opened. 
c.  The  situation  of  the  punc- 
ta  lachrymalia,  or  the  holes  at 
the  inner  angles  of  the  lids, 
through  which  the  tears  flow, 
to  get  into  the  tube  which 
finally  conveys  the  fluid  to  the 
nose. 

dd.  The  ducts  continued  from 
th e pun ctet  lachrymalia. 

ee.  The  angles  which  the 
ducts  form  after  leaving  the 
puncta. 

f.  The  termination  of  the  lachrymal  ducts  in  gg. 
gg.  The  lachrymal  sac. 

h.  The  nasal  duct,  continued  from  the  lachrymal  sac. 


WHY  DO  AGED  PERSONS  ’REQUIRE  CONVEX  GLASSES? 

Age  gradually  relaxes  the  tension  of  the  whole  system  ; 
the  eye,  therefore,  suffers  in  a corresponding  ratio.  The 
cornea  becomes  less  prominent: — the  convexity  of  the 
lens  is  also  diminished,  and  the  rays  of  light  are  conse- 
quently less  convergent  than  formerly.  The  picture  of 
the  object  is  faint,  because  the  rays  have  a tendency,  by 
their  divergency,  to  impinge  at  a supposable  plane,  be- 
yond the  retina. 


ANATOMICAL  CLASS  BOOK. 


229 


Fig.  90. 


In  this  figure  is  represented  the  effect  of  old  age  on  the  humors; 
without  the  intervention  of  the  glass  A,  the  rays  have  a direction 
which  would  form  the  image  at  some  distance  beyond  the  retina , as 
at  B.  But,  by  the  convex  glass  A,  which,  for  example,  is  the  spec- 
tacle worn  by  aged  people,  (he  direction  of  the  rays  of  light  is  so 
corrected,  that  the  image  falls  accurately  on  the  bottom  of  the  eve, 
or  retina. 

When  the  convex  lens  is  interposed  between  the  eye 
and  object,  as  represented  in  the  above  diagram,  the  rays 
are  made  more  converging,  — so  that  the  picture  strikes 
exactly  and  distinctly  on  the  nerve.  People  slide  their 
spectacles  on  the  nose  unconsciously  till  the  true  focus  is 
procured. 

WHY  DO  NEAR-SIGHTED  PERSONS  SEE  INDISTINCTLY? 

Either  the  crystaline  lens,  but  more  generally  the  cor- 
nea, is  too  prominent  — converging  the  light  too  sudden- 
ly ; — that  is,  converging  the  luminous  rays  at  an  unnatural 
place  within  the  vitreous  humor.  An  indistinct  outline  of 
the  object  is  the  effect  of  their  great  divergency,  after 
decussating — before  they  arrive  at  the  retina.  The  fol- 
lowing diagrams  will  illustrate  the  subject  far  better  than 
a whole  volume  of  written  explanations. 


Fig.  91. 


20 


230 


ANATOMICAL  CLASS  BOOK. 


Explanations  of  Fig.  91. 

In  this  figure,  the  convexity  of  the  cornea,  or  the  focal  powers 
of  the  lens,  being  too  great  for  the  length  of  the  axis  of  the  eye,  the 
image  is  formed  at  A,  before  the  rays  reach  the  surface  of  the  retina, 
or  inner  box,  illustrated  in  Fig.  81,  letter  c ; and  after  coming  accu- 
rately to  the  point,  they  again  begin  to  diverge  ; which  diverging 
rays,  striking  the  surface  of  the  retina,  give  the  indistinct  vision  of 
the  near-sighted  individual.  But  as  this  indistinctness  of  vision 
proceeds  from  no  opacity,  but  only  the  disproportion  of  the  convexity 
of  the  eye  to  the  diameter,  the  defect  is  corrected  by  a concave  glass, 
represented  in  the  next  figure. 

Concave  glasses  are  the  restoratives  of  the  near-sighted 
eye,  by  separating  the  rays,  and  carrying  the  image  so 
far  back  as  to  place  it  on  the  retina.  Old  age,  the  de- 
struction of  the  first  eye,  eventually  restores  the  near- 
sighted, by  the  gradual  flattening  of  the  cornea,  till  at 
threescore  and  ten  such  persons  can  see  clearly  and 
distinctly  without  artificial  aid.  Many  near-sighted  people 
totally  ruin  the  organ  by  prematurely  wearing  glasses,  as 
a focus  is  established  which  neither  glasses  can  keep 
pace  with  in  age,  nor  age  thoroughly  overcome. 


Explanations  of  Fig.  92. 

The  effect  of  this  glass  being  exactly  the  reverse  of  the  convex, 
it  causes  the  rays  to  fall  upon  the  surface  of  the  eye,  so  far  diverg- 
ing from  the  perpendicular  line,  as  to  correct  the  too  great  converg- 
ence, caused  by  the  convexity  of  the  humors.  When  a near-sighted 
person  has  brought  the  object  near  enough  (o  the  eye  to  see  it  dis- 
tinctly, he  sees  more  minutely  and  consequently  more  clearly, 
because  he  sees  the  object  larger,  and  as  a person  with  a common 
eye  does,  when  assisted  with  a magnifying  glass.  A near-sighted 
person  sees  distant  objects  indistinctly,  and,  as  the  eye,  in  conse- 
quence, rests  with  less  accuracy  upon  surrounding  objects,  the 
piercing  look  of  the  eye  is  very  much  diminished;  and  it  has,  more- 
over, a dulness  and  heaviness  of  aspect.  Again,  the  near-sighted 
person  knits  his  eye-brows,  and  half  closes  the  eye-lids  y this  he 
does  unconsciously,  to  change  the  direction  of  the  rays,  and  to  cor- 


ANATOMICAL  CLASS  BOOK. 


231 


rect  the  inaccuracy  of  the  image.  Near-sighted  people  have  but 
little  expression  ; the  countenance  loses  all  its  dignity,  by  habitually 
wearing  glasses. 

THE  IMAGE  OF  AN  OBJECT  IN  THE  EYE,  IS  INVERTED. 

Rays  of  light  going  from  the  upper  and  lower  points  of 
an  object,  are  refracted  towards  the  perpendicular : that  is, 
bent  out  of  the  course  which  they  have  a tendency  to 
run,  by  the  crystaline  lens  behind,  where  they  unite  in 
a point,  — and,  then  crossing,  diverge  again.  Here  then, 
the  image  is  bottom  upward,  as  will  be  noticed  in  the 
preceding  diagrams  by  the  arrow',  and  its  image  on  the 
retina.  Decussation  is  indispensable  to  the  vision  of 
things.  An  object  could  not  be  represented  on  a point  ; 
there  must  be  surface  to  create  an  image  on,  and  by  the 
laws  of  optics,  the  representation  of  the  object,  without  an 
additional  glass  within  the  eye,  must  necessarily  be  as  it 
is  — bottom  upward. 

THE  OBJECT  APPEARS  IN  ITS  TRUE  POSITION. 

Habit  is  supposed  to  be  the  cause  of  seeing  objects  as 
they  really  exist  in  relation  to  surrounding  bodies.  An 
attempt  has  been  made  to  prove  that  the  cornea  is  the  true 
seat  of  vision,  and  that  we  see  by  means  of  erect  and  re- 
flected, and  not  by  refracted  and  inverted  images.  A few 
philosophers  conceive  that  the  mind  contemplates  the  ob- 
ject only,  without  reference  to  its  representative  on  the 
retina,  which  is  made  there  as  a natural  result.  Certain 
it  is,  that  without  the  image,  there  is  no  vision. 

How  the  brain  is  operated  upon  by  the  light  that  de- 
fines the  object,  will  probably  never  be  known.  The 
minuteness  of  the  picture  traced  on  the  retina,  precisely 
like  the  object  in  every  minute  particular,  is  truly  aston- 
ishing. By  cutting  off  the  coats  of  a bullock’s  eye  and 


232 


ANATOMICAL  CLASS  BOOK. 


holding  a clean  white  paper  near,  this  beautiful  exhibition 
can  be  leisurely  observed.  If  a sheet  of  white  cotton  cloth, 
six  feet  square,  is  elevated  24,000  feet  in  the  air,  the  eye 
being  supposed  one  inch  in  diameter,  the  miniature  of  the 
cloth  on  the  retina  will  be  only  one  eight  thousandth  part 
of  an  inch  square  ; which  is  equivalent  to  the  666th  part 
of  a line, — being  only  the  66th  part  of  the  width  of  a 
common  hair ! 

WITH  BOTH  EYES  ON Llr  ONE  OBJECT  IS  SEEN. 

At  one  side  of  the  centre  of  each  eye,  there  is  a surface 
more  susceptible  of  visual  impressions  than  any  other. 
These  points  correspond  in  both  eyes — being  precisely 
on  the  two  retinas  alike.  An  impression  therefore  on  one, 
provided  the  light  strikes  them  equally,  produces  precisely 
the  same  effect  on  both.  This,  instead  of  making  vexa- 
tion, gives  strength  and  greater  vividness,  as  the  images 
are  on  surfaces  of  the  same  structure,  transmitting,  through 
the  two  optic  nerves,  the  same  idea,  or  that  indescribable 
something  that  creates  an  idea.  The  optic  axes,  by  this 
explanation,  will  be  understood.  If  one  eye  is  distorted, 
— pressed  by  the  finger  one  side,  when  we  are  in  the  act 
of  contemplating  an  object,  it  will  appear  double,  but  less 
distinct  in  the  one  so  distorted.  The  rationale  is  this  ; 
viz.  the  visual  surface  on  which  the  image  is  made,  so 
exactly  alike  in  both  eyes,  as  to  call  up  but  one  idea,  being 
forced  out  of  the  optic  axis,  the  rays  still  make  the  pic- 
ture, but  on  a surface,  less  highly  organized,  — that  does 
not  correspond  with  the  surface  on  that  retina  which  has 
not  been  disturbed.  The  two  images  have  now  different 
localities.  No  course  of  experiments  are  more  within  the 
reach  of  the  scholar. 


ANATOMICAL  CLASS  BOOK. 


233 


Fig.  93. 


the  same  relation  to  the  retinas 


Explanation  of  Fig.  93. 

In  this  figure,  B,  B.  the  eyes; 
having  their  axes  directed  to  A, 
will  see  the  object  C,  double,  some- 
where near  the  outline  D,  D.  Be- 
cause the  line  of  the  direction  of 
the  rays  from  C,  do  not  strike  the 
retina  in  the  same  relation  to  the 
axis  A,  B,  in  both  eyes.  If  a can- 
dle is  placed  at  the  distance  of  ten 
feet,  and  I hold  my  finger  at  arm’s 
length,  between  the  eye  and  the 
candle,  when  I look  at  the  candle, 
my  finger  appears  double,  and 
when  I look  at  the  finger,  the  can- 
dle is  double. 


Explanation  of  Fig.  94. 

A is  exactly  in  the  centre  of  the 
axes  of  both  eyes  ; consequently  it 
is  distinctly  seen,  and  it  also  ap- 
pears single,  because  the  form  of  it 
strikes  upon  the  points  of  the  retina, 
opposite  to  the  pupils  in  both  eyes. 
Those  points  have  a correspond- 
ence, and  the  object  is  strengthened 
in  the  liveliness  of  the  image. 
Again,  the  object  B will  be  seen 
fainter,  but  single  and  correct.  It 
will  appear  so  because  there  is  only 
one  spot  in  each  eye,  which  pos- 
sesses the  degree  of  sensibility  ne- 
cessary to  perfect  vi-ion;  thus,  it 
will  be  understood,  the  object  will 
appear  single,  as  the  rays  of  light 
proceeding  from  it  have  exactly 
in  both  eyes. 


CROSS-EyED  PERSONS  SEE  ONLY  WITH  ONE  EYE. 

With  such  as  have  a permanent  squint,  (cross-eye,)  only 
one  eye  is  attended  to,  though  they  may  not  be  apprehen- 
sive of  the  fact.  From  continued  neglect,  the  distorted 
organ  wanders  farther  and  farther  from  the  axis  of  vision, 
20* 


234 


ANATOMICAL  CLASS  BOOK. 


till  it  finally  becomes  totally  useless:  hence  one  is  doubt- 
ful, at  times,  which  way  the  cross-eyed  person  is  looking, 
from  a want  of  parallelism  in  the  motions  of  the  eyes. 
When  the  wandering  eye  is  exclusively  attended  to,  the 
vision  appears  unimpaired.  The  image  is  well  painted  in 
the  natural  one,  but  weak  in  the  other,  solely  because  the 
place  of  the  image  does  not  correspond  with  the  place  of 
the  image  in  the  first.  The  mind,  instinctively,  therefore, 
is  devoted  to  the  eye  that  gives  the  liveliest  impression,  to 
the  entire  neglect  of  its  aberrating  fellow. 

THE  PUPILS  OF  AN  ALBINO’S  EYES  ARE  RED. 

If  a person  is  born  without  the  pigmentum  nigrum, — 
which  is  the  paint  to  suffocate  all  unnecessary  light,  after 
the  image  is  formed,  — the  blood  vessels  of  which  the 
tunica  choroides  or  second  coat  is  made,  are  not  hidden ; 
consequently,  they  show  through  the  transparent  humors, 
like  a sparkling  red  gem,  the  size  of  the  diameter  of  the 
pupil.  Such  persons  can  see  better  in  a weak  light  than 
in  broad  day,  because  the  brightness  of  the  sun’s  light 
dazzles,  and  produces  a tremulous  motion  in  the  whole  or- 
gan. As  an  evidence  that  this  redness  is  caused  by  the 
blood  in  the  vessels,  after  death,  when  it  coagulates,  the 
redness  in  a great  measure  disappears.  White  rabbits, 
white  mice,  besides  a vast  variety  of  birds,  have  no  pig- 
ment on  the  choroides,  and  are  therefore  distinguished  for 
red  pupils.  The  existence  of  the  pigmentum  nigrum,  is 
an  evidence  of  a day-seeing  eye.  In  man  the  want  of  it, 
constituting  the  albino,  is  an  anomaly. 

A morbid  action  of  the  absorbents  sorhetimes  removes 
the  paint,  and  the  pupil,  to  the  surprise  of  observers,  be- 
comes scarlet.  A partial  absorption  of  it  is  often  the 
cause  of  a diminution  of  the  original  powers  of  vision  . 
under  such  circumstances,  the  pupil  assumes  a bronze 


ANATOMICAL  CLASS  BOOK. 


235 


hue,  accompanied  by  a debility  and  tremor  of  the  globe 
under  the  influence  of  a moderate  degree  of  light. 

MANY  ANIMALS  SEE  IN  THE  DARK. 

Owls,  fishes,  cats,  bats,  &c,  instead  of  the  pigmentum 
nigrum,  have  a silvery  paint  of  a metallic  lustre,  where 
others  have  the  black  paint,  which  operates  like  a concave 
mirror,  in  reflecting  the  light  from  point  to  point,  within 
the  eye,  illuminating  it,  till  its  concentration  excites  the 
retina  to  perceive.  When  viewing  a cat’s  eyes  in  the  re- 
mote part  of  a dark  room,  there  are  certain  positions,  in 
which  they  are  seen  by  the  observer,  by  the  reflected  light 
within  themselves,  as  though  they  were  phosphorescent : 
their  brilliancy  is  very  peculiar.  Upon  the  principle  of  a 
looking-glass  behind  the  retina,  all  the  night  prowling  an- 
imals are  qualified  for  seeing  with  those  few  rays  of  light, 
which  the  constitution  of  their  eyes  is  formed  for  collect- 
ing in  the  dark.  By  daylight,  they  perceive  objects,  as 
man  does  in  the  dark,  indistinctly. 

Nature  is  remarkably  economical  in  the  use  of  matter 
which  enters  into  the  composition  of  animal  bodies.  Jf  a 
man  be  kept  a long  time  in  a perfectly  dark  room,  the 
black  pigment  is  taken  away;  but  a compensation  is  giv- 
en him,  for  he  can  then  see  as  perfectly  in  the  dark,  as  he 
could  before  in  the  light.  On  the  other  hand,  the  paint 
is  deposited  again  when  he  is  restored  to  the  light  of  day. 
This  point  has  been  decided  in  the  persons  of  state  pris- 
oners kept  in  the  dungeons  of  European  despots. 

FISHES  CANNOT  SEE  IN  AIR  AS  WELL  AS  IN  WATER. 

When  the  rays  of  light  pass  from  a rarer  to  a denser 
medium,  as  from  air  into  the  aqueous  humor  of  the  eye, 
they  are  refracted  towards  the  perpendicular.  Now  the 
fish  has  but  a drop  as  it  were,  of  aqueous  humor,  and, 


236 


ANATOMICAL  CLASS  BOOK. 


moreover,  the  light  arrives  at  its  eyes  through  the  whole 
body  of  water  above.  The  light  is  refracted  only  in  a 
small  degree  in  entering  its  eye,  because  the  humor  is  of 
the  same  density  of  the  fluid  through  which  the  light  is 
transmitted.  The  cornea  is  quite  flat ; if  it  were  promi- 
nent, like  the  human  eye,  the  sphere  of  vision  would  be 
too  circumscribed;  — but  by  giving  a prominence  to  the 
whole,  and  placing  the  crystal ine  lens  in  the  fore  part 
of  the  eye,  they  have  a long  diameter, — and  with  the 
provision  of  a large  pupil,  are  completely  fitted  for  seeing 
in  the  element  in  which  they  were  destined  to  live.  With 
an  eye  of  this  description  they  must  necessarily  see  in  air, 
as  other  animals  see  in  water. 

Those  animals  whose  eyes  are  organized  for  seeing  in 
water,  see  but  indifferently  in  air.  Hence,  in  those  cases 
where  the  habits  of  the  animal  require  it  to  see  in  both 
elements  it  is  provided  with  two  sets  of  eyes,  or  with  eyes 
accommodated  for  seeing  in  both. 

It  cannot  be  denied,  that,  in  general,  land  animals  can 
see  under  water,  and  aquatic  animals  in  air;  even  man 
sees  under  water,  although  the  contrary  has  been  main- 
tained. It  is  not,  however,  possible  that  the  same  eye  is 
ever  so  organized  as  to  see  equally  well  in  both  elements. 
Land  animals  always  see  indifferently  in  water,  and 
aquatic  animals  imperfectly  in  air.  The  one  is  long- 
sighted in  water,  and  the  other  short-sighted  in  air.  An 
animal  in  which  the  eye  is  adapted  for  seeing  equally  well 
in  air  and  water,  can  have  but  imperfect  vision  in  either. 
These  conclusions  are  in  conformity  with  what  is  known 
of  the  power  of  vision  in  those  animals  which  live  partly 
on  the  land  and  partly  in  the  water.  The  seal  lives  in 
both  elements;  but  it  has  but  imperfect  vision  in  the  air. 

We  have  the  most  satisfactory  evidence  of  the  short- 
sightedness of  seals,  from  a series  of  experiments  and  ob- 
servations, made  in  Boston  harbor. 


ANATOMICAL  CLASS  BOOK. 


237 


As  a light  looses  more  of  its  power  in  passing  through 
water,  than  in  passing  through  air,  and  is  still  more  weak- 
ened in  its  progress  through  the  membranes,  it  follows, 
that  owing  to  this  cause,  vision  must  be  less  distinct  un- 
der water  than  in  the  air. 

MAN  CANNOT  SEE  DISTINCTLY  UNDER  WATER. 

A man  under  water,  sees  objects  as  a very  aged  per- 
son sees  through  a concave  glass,  placed  close  to  the  eye. 
The  fish  is  long-sighted  under  water,  and  man  is  short- 
sighted. If  he  uses  spectacles,  whose  convexity  is  just 
equal  on  both  sides  to  the  cornea  of  his  own  eye,  he  will 
see  under  water  distinctly.  The  necessity  of  this  is  ob- 
vious ; the  aqueous  humor  is  of  the  same  density  with  the 
water,  and  there  cannot,  therefore,  be  any  refraction  of 
the  rays  in  passing  from  the  water  into  the  land-seeing 
eye. 

Euclid  supposed  that  vision  was  occasioned  by  the 
emission  of  rays  from  the  eye  to  the  object.  He  thought 
it  more  natural  to  suppose  that  an  animate  substance  gave 
an  emanation,  than  that  an  inanimate  one  did.  In  1560, 
the  opinion  that  the  rays  entered  the  eye,  was  established. 
Kepler,  in  1600,  showed,  geometrically,  how  the  rays 
were  refracted  through  all  the  humors,  so  as  to  form  a dis- 
stinct  picture  on  the  retina ; and  he  also  demonstrated 
the  effect  of  glasses  on  the  eyes. 

HOW  DOES  THE  EYE  ADAPT  ITSELF  TO  THE  DISTANCE  OF 
OBJECTS. 

No  one  has  satisfactorily  answered  this  question.  One 
philosopher  supposes  the  eye  at  rest,  when  we" examine  a 
distant  object,  as  a mountain,  the  spire  of  a church,  or  a 
landscape,  but,  that  in  the  act  of  seeing  near  objects, 
there  is  an  effort.  It  has  been  supposed  that  this  effort 


ANATOMICAL  CLASS  BOOK. 


238 

is  the  action  of  the  straight  muscles,  exhibited  in  the  first 
plan  of  the  cordage  of  the  eye,  compressing  the  globe,  so 
equally,  as  to  elongate  the  eye,  and  lengthen  the  axis,  so 
much,  as  to  favor  the  union  of  the  pencils  of  rays  on  the 
retina.  This  could  not  take  place  in  many  aquatic  ani- 
mals, in  whose  eyes  the  sclerotica  is  perfect  bone. 

Another  opinion  is,  that  the  eye  is  at  rest  in  looking  at 
near  objects,  and  laboring,  when  viewing  things  at  a dis- 
tance. Another  is  of  the  opinion  that  the  iris  contracts, 
and  so  draws  the  circular  margin  of  the  cornea  towards 
the  pupil,  as  to  make  it  more  or  less  convex,  according 
to  circumstances.  A great  variety  of  experiments  have 
been  instituted,  to  determine,  accurately,  whether  there 
really  is  any  change  made  in  the  length  of  the  axis  of  the 
eye-ball  or  not,  but  none  of  them  can  be  certainly  relied 
upon.  A favorite  theory  has  had  its  advocates,  that  the 
crystaline  lens  has  an  inherent  power  of  altering  its  de- 
gree of  convexity  ; and  thus  accommodates  the  eye  to  all 
distances.  The  truth  is,  an  action  takes  place  in  the  eye, 
in  adapting  itself  to  near  and  distant  objects,  which  de- 
pends on  that  vital  property  of  a living  system,  which  no 
theory  can  reach,  and  which  the  deductions  of  human 
philosophy  can  never  with  certainty  explain. 


/ 


ANATOMICAL  CLASS  BOOK. 


239 


QUESTIONS. 


How  many  coats  has  the  eye  ? 

What  is  the  cornea  ? 

How  many  humors  has  the  eye  ? 

What  is  the  office  of  the  lens  ? 

What  is  the  retina  ? 

What  do  you  understand  by  the  pupil  ? 

Where  is  the  iris  located  ? 

What  is  the  use  of  the  ciliary  process  ? 

Where  is  the  pigment  found  ? 

Why  is  the  pupil  red  in  the  albino  ? 

What  is  the  function  of  the  iris  ? 

Why  is  but  one  object  seen  with  both  eyes  ? 

What  is  the  cause  of  squinting  ? 

How  are  some  animals  able  to  see  in  the  dark  ? 

Why  cannot  a man  see  under  water? 

Why  are  convex  spectacles  necessary  for  the  aged  ? 
What  causes  near-sightedness  ? 

On  what  does  the  color  of  the  eye  depend? 

What  is  the  position  of  the  image  on  the  retina  ? 
How  does  the  eye  alter  its  focus  ? 

What  is  the  use  of  the  aqueous  humor  ? 

On  what  does  the  brilliancy  of  the  organ  depend  ? 
Where  are  the  tears  secreted  ? 

What  is  the  effect  of  distorting  one  eye  ? 

How  many  muscles  are  attached  to  the  globe  ? 


240 


ANATOMICAL  CLASS  BOOK. 


FEELING,  OR  TOUCH. 

Touch  is  a sensation  excited  by  the  contact  of  bod- 
ies, by  which  we  are  enabled  to  appreciate  their  various 
qualities,  as  hard,  soft,  — heat,  cold,  wet  and  dry.  The 
immediate  seat  of  this  sense,  is  at  the  point  where  the 
nerves  terminate  in  little  papillae,  and  therefore  most  per- 
fect at  the  points  of  the  fingers.  This  sense  is  undergoing 
incessant  changes,  from  infancy  to  age. 

That  general  sense  of  feeling  over  all  the  surface  of  the 
body,  by  which  we  can  designate  the  forms  and  other 
characters  of  substances  brought  in  contact  with  the  skin, 
we  define  to  be  perception. 

SMELLING. 

Perhaps  the  sense  of  smelling  is  of  the  least  conse- 
quence to  man,  of  all  his  senses  : nature  designed  it  and 
placed  it  as  a safeguard  over  the  stomach,  — to  detect  the 
hurtful  from  the  wholesome  food,  — and  in  savages  it  an- 
swers this  purpose,  being  always  in  requisition.  In  civil- 
ized life,  however,  it  is  of  very  little  consequence.  Its 
importance  to  brutes  is  manifested  continually. 


ANATOMICAL  CLASS  BOOK. 


241 


T A S T I NG. 


This  sense  resides  in  the  tongue, on  which  the  gustatory 
nerve  terminates,  in  the  form  of  very  small  tubercles,  be- 
ginning at  the  point  and  reaching  quite  into  the  throat.  By 
it  we  distinguish  certain  qualities,  as  sioeet , sour,  bitter, 
acrid,  &c.  Before  the  sensation  is  complete,  the  sub- 
stance is  necessarily  dissolved  in  the  saliva  of  the  mouth, 
by  which  means  it  is  uniformly  presented  to  the  nervous 
papillae. 


21 


242 


ANATOMICAL  CLASS  BOOK. 


THE  GLANDS, 

OR  ADENOLOGY. 

Glands  are  generally  round,  fatty  bodies,  placed  at  short 
distances  both  internally  and  externally,  — whose  function 
is  either  to  secrete  a fluid,  or  change  the  quality  of  that 
which  has  been  collected  by  another  gland  in  the  neigh- 
borhood. Thus,  the  salivary  glands  about  the  inside  of 
the  cheek,  and  below  the  tongue,  secrete  the  saliva  of  the 
mouth.  The  lachrymal  glands  secrete  the  tears,  and  the 
mucus  glands  secrete  mucus.  Their  importance  in  the 
animal  economy  is  very  great.  Tumefactions,  or  sudden 
swellings  of  glands  by  severe  colds,  indicate,  by  the  de- 
rangement they  cause  to  other  organs,  their  high  con- 
sequence. 

INTERNAL  ORGANS,  OR  SPLANCHNOLOGY. 

Under  this  division,  is  embraced  the  viscera  or  con- 
tents of  the  three  great  cavities,  viz,  in  the  head,  chest 
and  abdomen.  Of  the  contents  of  the  skull,  we  have  al- 
ready treated. 


VISCERA  OF  TIIE  THORAX. 

Within  the  thorax  or  chest  which  is  bounded  by  the 


ANATOMICAL  CLASS  BOOK. 


243 


neck  above  and  the  diaphragm  or  midrif  below,  are  con- 
tained the  following  organs,  viz  ; the  pleura , lungs,  heart , 
thymus  gland,  (Esophagus,  thoracic  duct,  arch  of  the  aorta, 
branches  of  the  cava,  vena  azygos,  eight  pair  of  nerves  and 
part  of  the  sympathetic  nerve. 

PLEURA. 

Two  membranous  sacks  are  lodged  in  the  chest,  one 
on  either  side,  attached  closely  to  the  ribs,  but  their  sides 
meeting  in  the  middle,  under  the  breast  bone,  unite  and 
form  a partition,  called  mediastinum.  Thus  the  chest  is 
lined,  so  that  each  lung  has  an  independent  apartment. 

The  heart,  enclosed  in  its  case,  lies  in  a triangular 
space  between  the  two  lungs. 

DIAPHRAGM. 

This  is  nearly  a horizontal  partition  between  the  chest 
and  abdomen,  and  is  perfectly  muscular.  Its  border  ad- 
heres to  the  ribs,  breast  bone  and  spine.  Through  it, 
near  the  spine,  are  openings  for  the  passage  of  the  swal- 
low, blood-vessels  and  nerves. 

The  diaphragm  is  a muscle  of  respiratiom,  — rising  up- 
ward, as  the  lungs  collapse,  and  falling  down  again,  as  the 
lungs  become  inflated. 

LUNGS. 

There  are  two  membranous  organs,  by  which  breath 
ing  is  effected.  The  physiology  of  the  function  of  the 
lungs  has  been  considered,  in  detail  with  the  circulation 
of  the  blood.  They  are  divided  into  right  and  left : the 
right  lung  has  three  lobes,  but  the  left,  only  two.  They 
seem  to  be  made  up  of  a spongy  substance,  air  tubes  and 
blood-vessels.  Their  use  cannot  be  misapprehended. 


244 


ANATOMICAL  CLASS  BOOK. 


By  respiration  is  meant  the  ingress  of  air  into  the  lungs, 
and  by  expiration  its  egress  from  them. 

Voluntary  respiration  depends  upon  the  will,  when  we 
are  awake,  but  spontaneous,  is  the  respiration  of  sleep. 
It  is  thought  that  the  exciting  cause  of  the  process,  is  the 
irritation  of  the  nerves  in  the  air  cells,  which  by  a consent 
of  parts,  gains  the  assistance  of  the  diaphragm  and  inter- 
costal muscles  and  vibs,  to  expel  it.  The  object  of  respi- 
ration, is  the  oxygenation  of  the  blood.  Though  the  vital 
temperature  of  the  body  cannot  be  readily  accounted  for, 
it  is  generally  admitted  that  heat  is  developed  by  the  action 
of  the  atmospheric  air  on  the  volume  of  blood  exposed  to 
its  influence  with  the  air  cells. 

As  an  introduction  to  a description  of  the  vocal  apparatus 
of  man,  and  other  animals,  it  seems  necessary,  first,  to 
explain  both  the  process  of  breathing,  and  its  necessity, 
in  the  animal  economy  : because,  in  the  sequel  it  will  be 
apparent,  that  without  lungs,  there  could  be  no  voice. 

Such  is  the  constitution  of  every  living  creature,  that  a 
free  use  of  atmospheric  air  is  absolutely  necessary  for  sus- 
taining life.  The  mere  circumstance  of  being  surrounded 
by  air  is  not  sufficient ; if  it  were,  there  would  be  various 
ingenious  devices  for  maintaining  life,  after  the  lungs 
were  rendered  useless  by  disease  or  accident. 

It  is  absolutely  necessary  that  air  should  be  taken  into 
the  system,  and  brougJat  in  contact  with  the  moving  blood. 
The  various  modes  by  which  nature  has  accomplished 
this,  in  the  mechanism  of  some  animals,  will  now  be  con- 
sidered. 

If  Spallanzani  and  some  others  are  to  be  credited,  in 
their  accounts  of  what  they  discovered  by  the  microscope, 
we  have  the  first  plan  of  a breathing  structure.  Spallan- 
zani, pretended  he  saw  the  respiration  of  animalcules  in 
vinegar.  They  were  shaped  like  stars,  and  in  the  centre 
of  each  were  two  dark  globular  spots,  one  of  which  he  con- 
ceived to  be  the  heart  pulsating,  and  the  other  the  lungs. 


ANATOMICAL  CLASS  BOOK. 


245 


Every  two  or  three  seconds,  to  use  his  own  words,  they 
were  slowly  blown  up,  three  or  four  times  their  natural 
size,  and  then  slowly  compressed  again.  A modern  phy- 
siologist remarks,  that  the  Abbe  must  have  forgotten  him- 
self in  assigning  them  lungs,  for  they  were  evidently 
aquatic  animals,  and  therefore  did  not  require  them. 

Passing  by  the  microscope  let  us  examine  something 
more  tangible,  — the  families  of  insects.  They  are  so 
organised  that  in  proportion  to  their  bulk,  they  require  a 
prodigious  supply  of  air.  The  heart  is  the  only  percepti- 
ble organ  in  flies  and  worms : how  their  breathing  organs 
are  constructed,  we  are  totally  ignorant. 

But  pertaining  to  that  apparatus,  the  existence  of  which 
cannot  be  questioned,  are  an  immense  number  of  air  tubes, 
coursing  over  and  through  every  part  of  them,  distinguish- 
able with  the  naked  eye,  resembling  white  lines.  It  is 
necessary  that  these  be  always  distended.  They  open, 
generally,  with  free  mouths,  on  the  sides  of  the  body,  and 
wherever  there  is  a ring  or  line,  it  marks  the  place  of  one 
of  them. 

In  worms,  it  also  appears  necessary  that  the  air  holes  or 
spirucula,  be  perfectly  free  and  open.  The  moment  a little 
varnish  is  applied,  ever  so  delicately,  to  the  last  holes,  that 
portion  towards  the  tail  is  paralyzed.  By  closing  the  next 
two,  another  ring  is  palsied  ; if  all  but  the  two  last,  to- 
wards the  head  are  closed,  it  still  lives,  though  it  cannot 
move  : but  when  the  last  of  the  series  are  closed,  it  dies 
immediately. 

Some  vermin  require  more  air,  judging  from  analogy, 
than  others  much  superior  in  size.  So  variously  are  the 
tubes  ramified,  that  the  viscera  appears  to  occupy  only 
about  one  fifth  of  the  whole  internal  cavity. 

Before  insects  arrive  to  their  perfect  state  of  existence, 
they  are  destined  to  undergo  several  interesting  changes. 
First  they  are  worms,  ordinarily  of  a loathsome  and  dis- 
21* 


246 


ANATOMICAL  CLjfSS  BOOK. 


gusting  appearance  ; and  lastly,  a beautiful  winged  insect, 
the  object  of  peculiar  admiration.  In  this  change,  there 
is  nothing  discoverable  to  the  philosopher  like  the  death 
and  resurrection  of  the  insect,  so  often  the  theme  of 
writers.  It  does  not  die,  while  undergoing  the  change, 
if  it  did,  the  process  would  never  be  perfected  : close  the 
spiracula  and  there  is  forever  an  end  to  its  existence. 

While  the  caterpillar  crawls  on  its  numerous  feet,  un- 
der its  coarse,  hairy  skin,  it  has  six  legs,  inimitably  folded 
next  the  body  ; — two  pair  of  wings,  that  only  require  the 
sun’s  rays  to  astonish  us  with  the  beauty  of  their  coloring  ; 
and  a proboscis,  nicely  packed  away,  to  sip  the  honey 
which  will  be  its  future  food.  The  period  finally  arrives, 
when  a development  of  these  embryo  organs  is  about  to 
take  place.  Some  inscrutable  sensation,  of  which  the 
worm  appears  to  have  an  instinctive  knowledge,  as  it 
seeks  a quiet,  safe  and  warm  retreat,  gives  it  a timely 
warning.  The  old  covering  becomes  dry  and  dark  ; the 
fluids  cease  to  circulate  in  it,  and  gradually,  as  the  legs 
and  wings  gain  freedom  within,  they  push  it  entirely  off ; 
— thus  disentangled,  it  flits  away  on  its  untried  wings, 
from  flower  to  flower. 

While  the  skin  was  drying,  the  worm  breathed  as  it 
did  before,  through  the  air  holes  of  the  old  covering. 

Insects,  it  is  supposed,  never  breathe  by  the  mouth. 
The  nymphae  of  gnats  can  raise  themselves  to  the  sutface 
of  a pool,  and  breathe  by  an  orifice  in  their  backs.  The 
hydrocanthiri  breathe  by  thrusting  their  tails  out  of  water. 
Bugs,  flies  and  worms  which  live  in  filth,  ditches,  and 
deep  under  ground,  breathe  the  pure  air  which  is  in  their 
air  tubes,  and  when  it  is  exhausted,  they  travel  near 
enough  to  the  surface  to  replenish  their  stock.  But  the 
maggot  of  the  eruca  labra  has  the  most  extraordinary  ap- 
paratus imaginable.  It  shoots  from  its  tail,  a tube,  resem- 
bling the  slides  of  a spyglass,  — one  beyond  another. 


ANATOMICAL  CLASS  BOOK. 


247 


The  last  has  a star-like  tuft  on  the  end,  which  unfolding 
on  the  water,  enables  it,  thus  buoyed  up^to  breathe  freely, 
while  it  floats  about  at  pleasure,  — in  search  of  food. 

Fishes  are  without  lungs,  and  yet  they  require  a constant 
supply  of  air,  though  in  a lesser  quantity  than  animals  with 
a double  heart.  Such  is  their  peculiarity  of  structure, 
that  they  breathe  a mixture  of  air  and  water  together. 
The  gills  enable  them  to  perform  this  process.  Deprive 
water  of  its  air,  and  the  fish  dies  as  soon  as  it  would  out 
of  water.  The  free  exposure  of  the  gills  to  water  is  not 
sufficient  : it  is  necessary  to  propel  the  water  through  them 
forcibly.  If  the  feathery  gills  of  a small  perch  could  be 
unfolded  and  spread,  it  is  not  improbable  that  they  would 
cover  a square  yard.  This  will  not  appear  so  extraordinary, 
when  it  is  recollected  that  the  nerve  in  a dog’s  nose,  is 
spread  into  so  thin  a web,  that  it  is  computed  to  be  four 
yards  square.  Observe  the  wonderful  economy  of  nature ; 
this  web  is  so  rolled  up,  like  a scroll  of  parchment,  that  it 
could  be  packed  away  in  a lady’s  thimble. 

Nearly  one  third  of  all  the  blood  is  exposed  to  the  ac- 
tion of  the  air,  in  the  gills,  at  the  same  time.  The  fish 
draws  in  a mouthful  of  water,  and  with  a quick  motion,  by 
closing  the  jaws,  drives  it  through  the  gills,  and  this  im- 
parts vitality,  and  restores  the  red  color  to  the  dark  blood 
of  the  veins. 

Various  tribes  of  fishes  which  seek  their  food  in  the 
mud,  and  foetid,  turbid  water,  have  a striking  provision  for 
defending  their  gills;  otherwise  they  would  become  clog- 
ged, and  breathing  would  be  interrupted  by  the  very  filth 
in  which  they  were  actually  created  to  live.  Their  gills 
are  small,  and  covered  by  the  common  skin  of  the  body. 
The  water  is  taken  at  the  mouth,  and  driven  with  the 
same  force,  as  in  the  other  case,  but  emptied  through 
holes  on  each  side  of  the  neck,  just  back  of  the  jaws. 
The  force  is  always  sufficient,  by  dividing  the  water  into 


248 


ANATOMICAL  CLASS  BOOK. 


distinct  portions,  to  keep  the  openings  completely  clear. 
In  fact,  the  action  is  like  that  of  an  apothecary’s  syringe. 
A familiar  example  of  this  sort  of  animal  mechanism  may 
be  seen  in  the  lamprey  eel. 

A similar  breathing  apparatus  is  provided  for  shell  fishes, 
having,  however,  an  additional  contrivance,  by  which  they 
can  live  a considerable  time  out  of  water.  Here  let  the 
mechanism  be  particularly  noticed,  and  admired  too,  as 
the  first  step  towards  a terrestrial  animal.  As  those  in- 
habiting salt  water  are  necessarily  exposed,  by  the  reced- 
ing of  tides,  without  a limb  to  assist  them  in  regaining 
their  home,  and  so  organized  with  extensive  gills,  encir- 
cling two  thirds  the  circumference  of  the  shell,  that  they 
cannot  breathe  air,  their  apparently  helpless  condition  has 
been  provided  for  in  this  interesting  manner  ; viz.  they 
are  furnished  with  a long  elastic  pipe,  which  is  a reservoir 
for  water.  At  necessary  intervals,  the  fish  ejects  a drop 
with  surprising  force,  through  the  fringes  of  the  gills,  and 
then  remains  quiet,  till  some  instinctive  sensation  warns  it 
of  the  necessity  of  again  working  its  forcing  pump.  Being 
cold  blooded,  that  is,  having  the  single  heart,  one  throw 
of  the  brake  suffices  for  a long  time. 

In  travelling  over  a clam  bed,  at  low  tide,  the  tremor 
communicated  to  the  fish,  apprises  it  of  approaching  dan- 
ger, — and  the  nearer  the  observer  advances,  the  more 
distinctly  can  he  witness  the  amazing  projectile  force  with 
which  the  clam  drives  a little  column  of  water  up  through 
the  sand. 

This  is  only  part  of  the  contents  of  the  tube.  Nothing 
but  continued  irritation  will  induce  the  clam  to  part  with 
the  remainder,  — - which  is  noticed,  in  digging,  just  as  the 
shell  is  exposed  to  the  light. 

By  this  reserved  fund,  it  can  live  many  days,  in  open 
air.  It  is  by  this  tube  of  water,  that  the  oyster  is  kept 
alive  in  the  shops.  As  the  exposure  in  the  open  air, 


ANATOMICAL  CLASS  BOOK. 


249 


weakens  its  system,  it  recruits  itself,  by  jetting  a drop  of 
water  through  its  gills.  This  drop  may  be  seen  morning 
after  morning,  on  a dry  board  : — but  when  the  reservoir 
is  wholly  exhausted,  it  opens  its  shell,  fearless  of  conse- 
quences, and  seeks  in  despair,  wherever  it  can  reach,  a 
fountain,  to  replenish  its  engine  : — thus  it  languishes, 
and  at  last  dies,  a protracted  death,  in  search  of  its  ac- 
customed element. 

No  class  of  animals  are  more  wonderful  on  the  other 
hand,  than  the  amphibious.  They  live  alternately  in  two 
elements,  — hearing  and  seeing  tolerably  well  in  both. 
The  structure  of  some  of  their  organs  of  sense,  have 
already  been  considered.  But  it  is  not  true,  as  too  gene- 
rally believed,  that  they  alternately  respire  air  and  water, 
or  a mixture  of  both.  They  are  cold  blooded  animals,  it 
is  true,  with  a single  heart  — as,  for  example,  the  frog 
and  aquatic  lizards.  The  water  seems  to  be  their  peculiar 
element,  but  after  all,  they  breathe  the  air  exclusively. 
They  constitutionally  require  only  a small  quantity  of 
oxygen,  or  vital  air,  to  sustain  life,  and  keep  the  machinery 
in  operation.  They  have  lungs,  but  they  have  but  a faint  re- 
semblance to  those  having  warm  blood,  with  a double  heart. 

Their  lungs  are  merely  membranous  bags  or  cylinders, 
which  in  their  dry,  prepared  state,  appear  like  bubbles  of 
froth.  The  next  extraordinary  circumstance  is  this  — 
that  breathing  is  an  act  depending  on  the  will ; that  is, 
they  can  breathe  regularly,  at  short  intervals,  for  days 
together,  or  they  can  stop  the  respiratory  process  for  hours, 
or  perhaps  days,  and  continue  equally  vigorous. 

Fishes,  we  have  seen,  force  the  water  through  their 
gills:  the  same  process  of  forcing  air  into  these  membra- 
nous tubes,  is  accomplished  in  amphibious  animals,  by  a 
very  little  additional  mechanism  — the  mouth  acts  precisely 
like  a bellows.  The  jaws  are  grooved  above  and  below, 
that  they  may  be  air  tight,  and  a slit,  acting  like  a valve, 
is  placed  at  the  root  of  the  tongue,  over  the  wind-pipe 


250 


ANATOMICAL  CLASS  BOOK. 


leading  to  the  lungs.  Let  it  be  recollected  that  the  mouth 
is  never  opened,  except  for  food:  the  air  is  drawn  in 

through  very  small  nostrils,  which  in  the  frog  and  neut, 
are  not  larger  than  cambric  needles.  The  animal  slowly 
draws  its  mouth  full  of  air,  and  when  sufficiently  distend- 
ed, forces  it  through  the  valve,  hy  the  skin,  which  looks 
like  a pouch  under  the  lower  jaw. 

The  lungs  being  full,  give  additional  size  to  the  body. 
The  abdominal  muscles  re-act  and  slowly  press  it  out 
again,  and  thus  we  have  an  example  of  the  mode  by  which 
this  class  of  animals  breathe. 

If  the  frog’s  mouth  be  kept  open  with  a prop,  it  will 
inevitably  die,  as  there  is  no  power  by  which  it  can  inhale 
air,  short  of  the  bellows  of  its  jaws.  It  requires  no  phi- 
losophy, after  becoming  acquainted  with  these  interesting 
facts,  to  account  for  their  large  mouths  and  broad  jaws. 
No  other  shape  or  structure  would  so  completely  consti- 
tute the  bellows. 

Neuts,  lizards  and  the  camelion’s  lungs,  are  cylinders, 
running  down  the  sides  of  their  bodies,  the  whole  length, 
and  as  they  force  in  the  air  precisely  by  the  same  process, 
it  will  explain  the  reason  of  their  appearing  fat  at  one 
time,  or  thin  and  lank  at  another.  When  irritated,  or  in 
fear,  they  blow  up  their  bodies  to  frightful  dimensions,  to 
appear  more  formidable,  upon  the  same  instinctive  princi- 
ple that  cats,  dogs,  hedgehogs  and  fowls,  bristle  up  their 
covering  at  the  approach  of  an  enemy,  superior  to  them  in 
strength. 

The  different  colors  with  which  the  cantelion  so  readily 
dresses  itself,  depend  on  this  peculiarity  of  its  lungs.  The 
skin  is  covered  with  an  exquisitely  fine  covering,  like  vel- 
vet. If  the  lungs  be  filled  to  a certain  extent  the  swelling 
of  the  body  erects  the  fleece,  so  that  the  manner  in  which 
the  light  strikes  it,  makes  the  animal  appear  green,  white, 
or  of  other  colors:  another  blast  into  the  lungs,  gives 


ANATOMICAL  CLASS  BOOK. 


251 


another  inclination  to  the  fleece,  and  it  has  another  tint. 
When,  by  irritation,  its  body  is  blown  up  to  its  greatest 
dimensions,  various  modifications  of  these  colors  are 
exhibited. 

From  this  tribe  of  reptiles,  the  first  advance  is  made 
towards  endowing  animals  with  the  power  of  producing 
vocal  sounds.  The  water  is  only  capable  of  propagating 
a vibration,  but  that  with  great  certainty  and  strength,  and 
nature  has  constructed  an  ear,  suited  to  the  element  and 
the  habits  of  all  aquatic  beings.  To  have  bestowed  an 
ear,  susceptible  of  receiving  the  modification  of  sound, 
would  have  been  superfluous,  inasmuch  as  the  modifica- 
tions are  alone  effected  in  the  vocal  box  of  those  breath- 
ing air. 

The  atmosphere  is  the  medium  of  modified  sound  : it 
is  an  elastic  medium  which  can  be  put  in  motion  by  the 
vibration  of  solid  bodies.  It  is  a medium,  which,  when 
set  in  motion  by  a mechanical  contrivance  of  the  greatest 
apparent  simplicity,  transmits  the  wants  of  animals,  in 
what  is  denominated  its  natural  cry,  and  in  man,  expresses 
not  only  his  wants,  his  pleasures,  and  his  pains,  but  all  his 
thoughts,  — because  his  voice  represents  ideas.  Lan- 
guage, therefore,  is  the  symbol  of  thought. 

The  voice  of  all  animals  remains  the  same  through 
endless  generations,  unless  the  vocal  apparatus  is  artificial- 
ly altered.  Indeed  the  vocal  organs  are  so  constituted, 
that  they  admit  of  little  variety  in  their  movements:  — 
every  succeeding  class,  however,  exhibits  an  additional 
muscle,  a bone,  or  some  difference  in  the  shape  of  the 
tongue,  giving  it  the  power  of  either  making  one  more 
sound  than  the  race  below,  or  some  modulation  of  the 
original  tone.  Were  it  not  for  this  progression  in  the  con- 
trivance, the  voice  of  all  animals  would  be  precisely  the 
same,  like  sounding  one  note  continually  on  a musical 
instrument. 


252 


ANATOMICAL  CLASS  BOOK. 


Let  us  examine  another  curious  mode  of  respiration, 
peculiar  to  birds.  Although  there  is  an  external  resem- 
blance, in  the  shape  of  their  bones,  to  quadrupeds,  and 
the  muscles  Avhich  move  them  are  similarly  arranged,  to 
effect  a circle  of  motions,  their  structure  has  reference  to 
their  wafting  themselves  through  the  air. 

In  the  first  place,  the  long  bones  are  without  marrow  — 
being  hollow  tubes,  filled  with  air,  these  actually  have 
openings  communicating  with  the  lungs.  At  their  further 
extremities  they  permit  the  air  to  circulate  into  the  ends 
of  each  feather;  — and  lastly,  the  body  has  large  apart- 
ments exclusively  appropriated  for  the  reception  of  the 
same  air.  Their  lungs,  unlike  the  light  frothy  tube  of 
reptiles,  is  spongy  and  gorged  with  blood,  and  totally  un- 
like those  belonging  to  any  other  animal.  In  the  bird, 
the  lungs  are  open  at  each  end,'  and  are  so  closely  tied 
down  to  the  back  bone  and  ribs,  that  they  admit  of  little 
or  no  distention  or  contraction. 

Their  breathing  is  effected  in  the  following  manner; 
viz,  the  air  is  drawn  into  the  vacuum  caused  by  the 
pressure  of  the  strong  muscles  of  the  abdomen.  In  other 
words,  the  weight  of  the  atmosphere  forces  it  in,  so 
that  the  current  rushes  through  the  whole  length  of  the 
lungs,  where  the  blood  is  waiting  for  its  appearance,  and 
passes  to  the  extremities  of  all  the  bones  and  feathers. 
The  proper  change  being  wrought  in  the  venous  blood,  it  is 
circulated  again  to  the  heart,  while  the  muscles  again 
empty  the  lungs  and  air  cells,  contiguous,  by  a general 
compression  of  the  whole.  Here  is  discoverable  the  me- 
chanism for  producing  voice,  seen  in  its  elements  in  the 
frog,  improved  upon,  by  additional  cords  and  vibrating 
cartilages,  susceptible  of  receiving  a current  of  air,  in  a 
manner  a little  different,  to  produce  one,  two  or  three 
different  tones. 

Lastly,  nature  has  effected  respiration  by  a more  com- 


ANATOMICAL  CLASS  BOOK. 


253 


plex  piece  of  mechanism,  in  those  animals  whose  bodies 
are  divided  into  two  apartments  by  the  diaphragm. 

A difference  of  structure  does  not  appear  in  the  air  cells 
of  the  lungs  of  about  forty  varieties  of  animals,  including 
man.  The  only  circumstances  observable  relates  to  their 
shape  and  subdivisions,  depending  on  the  configuration  of 
the  cavity  in  which  they  are  lodged.  The  human  lungs 
are  suspended  in  the  chest,  much  as  they  are  in  brutes, 
by  the  wind-pipe,  and  so  tied  down  at  the  upper  part  of 
the  neck,  and  so  carefully  fitted  to  the  dimensions  of  the 
box,  in  which  they  are  lodged,  that  no  position  of  the  body 
can  throw  them  out  of  place.  There  is  a right  and  a left 
lung,  perfectly  independent  of  each  other,  and  separated 
by  a middle  partition. 

Exactly  in  the  centre  of  this  partition,  in  quadrupeds, 
the  heart  lies,  but  in  man,  it  is  on  the  left  side,  and  there- 
fore projects  into  the  cavity  of  the  left  lung.  They  are 
made  up  of  millions  of  air  cells,  which  are  filled  at  every 
inspiration.  The  blood,  directly  from  the  heart,  is  thrown 
into  them  in  prodigious  quantities,  and  circulates  so  mi- 
nutely, that  each  air  cell  is  completely  surrounded  by  a 
sheet  of  dark  blood. 


VOICE. 

We  shall  now  inspect  the  contrivance  by  which  sounds 
are  produced  by  animals. 

By  voice  animals  have  the  power  of  making  themselves 
understood  to  their  own  species — and  these  sounds  are 
either  articulate  or  inarticulate. 

Language  is  an  acquired  power,  having  its  origin  in  the 
wants  of  more  than  one  individual.  Man,  without  socie- 
ty, would  only  utter  a natural  cry,  which  sound  would 
express  nothing  but  pain. 

Supposing  a human  being  to  have  been  entirely  forsaken 

22 


254 


ANATOMICAL  CLASS  BOOK. 


by  those  of  his  species,  in  that  stage  of  infancy,  when  he 
could  have  no  recollection  of  anything  pertaining  to  his 
race,  his  voice  would,  in  essence,  remain  the  cry  of  an 
infant,  only  strengthened  in  tone,  at  a particular  age,  by 
the  development  of  the  vocal  organs,  to  their  destined 
size. 

But  let  two  individuals  bs  placed  together,  but  without 
communication  or  knowledge  of  the  existence  of  beings 
similar  to  themselves,  the  natural  cry  of  each  would  un- 
dergo modifications  : the  one  would  make  a sound,  to 
express  a particular  sensation,  which  in  time  would  be  un- 
derstood by  the  other  : a repetition  of  the  same  note 
would  be  the  sign  of  that  sensation  in  future. 

An  additional  sensation,  having  an  intimate  connexion 
with  the  first,  would  require  a variation  of  tone,  — and 
this  would  also  become  a symbol  of  two  sensations.  Here 
then  would  be  the  origin  of  language.  Multiply  the  spe- 
cies, and  each  new  member  of  the  society  would  express 
some  other  sensation  or  want,  by  another  modification  of 
the  original  cry.  Here  we  discover  the  certain  commence- 
ment of  a spoken  language  ; these  different  sounds  becom- 
ing classified,  constitute  a dictionary,  in  which  each  word 
is  the  mark  or  sign  of  particular  sounds;  — thus,  if  an  in- 
dividual can  imitate  the  sound-,  or  a series  of  sounds,  he 
masters  a language.  Let  it  be  remembered  that  man 
could  never  arrive  to  this  perfection  in  sound  or  language, 
if  his  vocal  organs  were  not  differently  constructed  from 
brutes.  Such  is  the  mechanism  of  theirs,  that  so  many 
sounds,  and  no  more,  can  be  made  ; but  in  man’s  organs, 
there  is  no  limitation  — no  sound  appreciable  that  he  can- 
not imitate. 

THE  VOCAL  BOX  OR  LARYNX. 

Directly  under  the  integuments  on  the  front  side  of  the 


ANATOMICAL  CLASS  BOOK. 


255 


neck,  is  a cartilaginous  tube,  the  trachea  or  wind-pipe, 
built  up  of  a series  of  narrow  strips,  which  are  portions  of 
a ring  ; therefore,  it  is  always  kept  free  and  open.  At  its 
lower  end  it  divides  into  two  branches,  going  to  the  lungs 
on  either  side,  but  its  upper  portion  is  enlarged,  just  under 
the  chin,  and  finally  opens  in  common  with  the  tube  of 
the  stomach  and  mouth.  This  enlarged  part,  quite  promi- 
nent in  man,  is  the  larynx  or  vocal  organ. 

Several  cartilages  assist  in  its  formation,  viz,  the  thyroid , 
cricoid,  th e arytoenoicl  and  the  epiglottis.  The  cricoid  is 
the  foundation  ; the  thyroid  is  the  wall  around  it ; the  ary- 
taenoid  are  appendages  to  the  back  of  the  cricoid,  and  the 
epiglottis  is  a valve,  opening  and  closing  the  entrance  into 
the  wind-pipe,  like  the  valve  of  a bellows. 

Explanation  of  Figs. 
95.  96. 

The  five  cartilages  are. 

1.  The  epiglottis. 

2.  The  thyroid  cartilage. 

3.  the  cricoid  auxiliary 
and 

4.  The  two  arytsenoid 
cartilages. 

5.  The  two  superior 
horns  of  the  thyroid  cartil- 
age. 

6.  The  two  inferior 
horns. 

7.  The  suspensory  liga- 
ment of  the  os  hyoides. 

8.  The  os  hyoides. 

9.  The  azj'gos  ligament, 
connecting  the  os  hyoides 
to  the  thyroid  cartilage. 

10.  The  two  lateral  liga- 
ments connecting  the  horns  of  the  os  hyoides  to  the  superior  horns 
of  the  thyroid  cartilage. 

One  of  these  diagrams  presents  a front  and  the  other  a back  view 
of  the  larynx  or  vocal  box.  The  hone  of  the  tongue  is  seen,  like 
half  of  a hoop  marked  S,  in  both  plans.  2 is  the  front  of  the  thyroid 
cartilage,  felt  under  the  skin  — protruding  in  the  form  of  an  irregu- 
lar tumor.  The  wind-pipe  is  the  tube  at  the  bottom  of  each  larynx. 


ANATOMICAL  CLASS  HOOK. 


256 

1 he  vocal  cords  — the  membranes  which  vibrate  to  produce  sound, 
as  the  current  of  air  rushes  by,  are  concealed,  being  placed  inside, 
b roni  the  remarks  in  the  text,  together  with  the  references,  a very 
correct  idea  will  be  formed  of  the  structure  of  this  curious  organ. 
By  blowing  through  the  wind-pipe  of  almost  any  animal,  soon  after 
it  is  slain,  provided  the  larynx  has  not  been  injured,  the  vocal  cords 
may  be  put  in  motion,  and  the  sound  which  is  produced  will  bear 
considerable  analogy  to  (he  natural  voice  of  the  animal. 

Within  the  larynx,  and  consequently  below  the  valve, 
are  four  delicate  membranes,  two  on  each  side,  put  upon 
the  stretch  — being  in  fact,  like  shelves,  — their  thin 
edges  nearly  meeting  from  the  opposite  sides,  so  that  there 
is  scarcely  any  space  between  them.  These  are  the  vocal 
cords. 

When  the  air  rushes  out  from  the  lungs  through  the 
wind-pipe,  it  must  obviously  pass  through  the  larynx,  — in 
doing  which  it  strikes  the  tense  edges  of  the  cords,  and 
produces  a vibration.  This  vibratory  motion  given  to  the 
current  of  air,  produces  sound.  In  the  cavities  of  the 
bones  of  the  face,  forehead  and  nose,  its  power  is  increased, 
and  in  the  mouth  it  undergoes  further  modifications,  and 
ultimately  becomes  articulate  language.  The  teeth, 
tongue,  lips,  nose  and  fauces  have  each  an  influence  in 
the  production  of  articulate  sounds.  Hence  grammarians 
have  arranged  the  human  voice  under  the  appropriate 
divisions  of  guttural,  nasal , dental  and  labial  sounds, — 
expressive  of  the  agency  which  each  of  these  organs  exert 
on  the  original  tone. 

Shrillness  or  roughnessof  voice  depends  on  the  diameter 
of  the  larynx,  — its  elasticity,  lubricity,  and  the  force  with 
which  the  expired  air  is  propelled  through  the  rima  glot- 
t-idis,  or  slit  like  chink,  between  the  vocal  cords. 

Because  the  larynx  is  smaller  in  women,  and  more  elas- 
tic, their  voice  is  of  a different  character.  The  breaking 
of  the  voice,  vox  rauca,  noticeable  in  boys,  at  a particu- 
lar age,  depends  partly  on  the  enlargement  of  the  apart- 


ANATOMICAL  CLASS  BOOK. 


257 


ments  within  the  bones,  which  generally  take  place  at  that 
important  crisis  of  their  lives,  when  the  whole  constitution 
undergoes  a sudden  change. 

But  the  mechanism  of  voice  would  have  been  incom- 
plete, were  there  not  a number  of  exceedingly  delicate 
muscles,  \vhich  graduate  the  diameter  of  the  narrow  slit 
through  which  the  sound  escapes  into  the  mouth.  Uncon- 
sciously, they  effect  the  requisite  contractions,  forever 
varying,  according  to  the  rapidity,  intensity,  or  strength  of 
the  voice,  in  singing,  conversation  or  declamation. 

Finally,  the  larynx  is  a musical  wind  instrument,  of  the 
reeded  kind,  on  the  principle  of  the  hautboy.  The  near- 
ness of  the  vocal  cords  to  each  other  resembles  the  reed 
precisely.  All  the  tones  of  reeded  instruments  are  effect- 
ed by  finger  holes,  — but  the  tones  of  the  human  voice 
are  varied  by  the  extrinsic  and  intrinsic  muscles,  which 
shorten  or  elongate  the  vocal  tube.  Thus  the  same  re- 
sult is  produced  by  this  process,  — increasing  or  diminish- 
ing the  diameter  of  the  larynx,  that  is  accomplished  in  the 
clarionet,  bassoon,  flute  and  hautboy,  by  a graduated 
scale  of  finger  holes. 

Is  not  this  another  beautiful  mechanical  evidence  of  the 
existence  of  a Being  superior  to  ourselves  ? 


22* 


258 


ANATOMICAL  CLASS  BOOK. 


THE  VISCERA, 

OR  SPLANCHNOLOGY. 


THE  FOOD-PIPE,  OR  .ESOPHAGUS. 

This  is  a fleshy  tube,  going  from  the  back  of  the  mouth 
to  the  stomach,  through  the  chest,  lying  in  the  neck  be- 
hind the  wind-pipe.  Its  upper  portion  is  called  the  pha- 
rynx, or  fauces,  and  its  lower,  the  cardiac  extremity,  termi- 
nating in  the  stomach. 

THYMUS  GLAND. 

Infants  and  young  children  possess  a singular  gland, 
located  just  behind  the  top  of  the  breast  bone,  which  has 
the  appellation  of  thymus  gland.  In  adults,  it  is  obliterated  ; 
hence  it  is  supposed  to  be  serviceable  only  in  the  early 
stages  of  our  existence. 

THORACIC  DUCT. 

Quite  low  in  the  abdomen  is  found  a white,  ex- 
quisitely delicate  tube,  which  runs  upward  by  the  side 


ANATOMICAL  CLASS  BOOK. 


259 


of  the  spine,  and  finally  terminates  by  communica- 
ting with  a large  vein  in  the  angle  between  the  neck 
and  shoulder,  on  the  left  side.  All  the  nutritious  sub- 
stance which  has  been  collected  from  the  food  in  the  in- 
testinal tube,  — now  called  chyle,  which  is  white  like 
milk,  is  conducted  to  this  thoracic  duct,  and  thence  car- 
ried on  to  be  poured  directly  into  the  circulation,  to  be- 
come blood. 


ABDOMEN. 

Bounded  by  the  diaphragm  above,  the  pelvic  bones  be- 
low and  the  muscles  at  the  sides,  the  abdomen  is  the  most 
capacious  of  all  the  cavities.  Its  lining  membrane  is  the 
■peritonaeum.  Various  organs,  principally  subservient  to 
digestion,  are  contained  within  it.  They  are  the  following. 

OMENTUM. 

Vulgarly,  the  omentum  is  the  cawl,  — a sort  of  apron 
lying  in  front  of  the  intestines,  suspended  mainly  from  the 
stomach. 

liver. 

Being  the  largest  and  heaviest  viscus  in  the  body,  the 
liver  has  also  a vast  influence  on  the  condition  of  the 
whole.  It  is  divided  into  right  and  left  lobes  — the  right 
is  the  largest,  and  occupies  the  right  side,  under  the  ribs. 
The  left  lobe  lies  partly  over  the  stomach,  in  the  other 
region.  Its  use  is  to  secrete  bile. 


260 


ANATOMICAL  CLASS  BOOK. 


Fig  97. 


ANATOMICAL  CLASS  BOOK. 


261 


Explanation  of  Fig.  97. 

In  this  view  of  the  abdomen,  d,  is  the  gall-bladder,  lying  on  the 
under  side  of  the  liver,  the  dark  mass  to  which  it  is  attached  : h is 
the  coronary  artery  which  supplies  the  stomach,  a,  b,  c,  with  blood. 
The  curve  ot  the  stomach  is  well  shown:  e,  e,  the  arteries  which 
supply  the  cawl,  marked  i,  i,  which  falls  down  from  the  front  of 
the  stomach,  over  the  intestines,  like  an  apron  : g,  a vessel  of  the 
liver.  The  pancreas  is  behind  the  stomach. 

GALL  BLADDER. 

This  is  attached  to  the  under  side  of  the  liver,  shaped 
like  a shot-pouch,  and  contains  between  one  and  two 
ounces  of  gall,  which  is  carried  to  it,  as  a place  of  deposit, 
from  the  liver.  A long  slender  pipe  extends  from  it  to 
the  duodenum,  the  first  portion  of  the  intestines,  into  which 
it  pours  the  bile.  The  use  of  the  bile  is  to  stimulate  the 
intestines,  in  order  to  keep  them  at  work. 

SPLEEN. 

Anatomists  have  not  discovered  the  function  of  this 
organ.  Generally,  however,  it  is  admitted  to  be  essentially 
serviceable  to  the  stomach.  The  color  is  red,  somewhat 
like  the  liver,  broad  as  the  palm  of  the  hand,  and  one  or 
two  inches  thick.  It  is  in  contact  with  the  stomach,  in 
the  left  side. 

PANCREAS. 

Behind  the  stomach,  lying  directly  across  the  spine,  is 
the  'pancreas,  a narrow  gland,  from  eight  to  ten  inches 
long, — which  secretes  a fluid  analogous  to  the  saliva. 
Through  a duct,  it  is  carried  onward  to  be  mixed  with 
the  bile  in  the  intestine.  It  is  regarded  as  an  auxiliary 
to  digestion. 


262 


ANATOMICAL  CLASS  BOOK. 


KIDNEYS. 

One  of  these  glands  is  placed  on  each  side,  in  the  loins, 
near  the  spine,  a little  above  the  hips.  From  the  trunk 
of  the  aorta,  the  great  artery  of  the  body,  two  large 
blanches  are  given  off,  nearly  at  right  angles,  to  the  kid- 
neys. A quantity  of  blood  is  therefore  sent  directly  into 
them,  from  which  the  urine  is  separated,  and  afterwards 
forced  through  the  ureters,  two  tubes  the  size  of  a writing 
quill,  ten  inches  or  more  in  length,  into  the  under  and 
back  part  of  the  bladder. 

The  urine  is  separated  from  the  blood  by  the  extreme- 
ties  of  the  arteries  within  the  substance  of  the  kidney. 
Having  remained  a while  in  the  bladder,  it  excites  a desire 
to  void  it,  — an  action  effected  chiefly  by  the  muscular 
fibres  of  the  bladder  itself,  assisted  by  the  abdominal 
muscles.  It  is  prevented  from  returning  from  the  bladder 
to  the-kidneys,  by  a valvular  structure  within,  continually 
closed  by  the  presence  of  the  fluid  against  the  valve. 


ANATOMICAL  CLASS  BOOK. 


263 


Fig.  98. 


■ </rj£ 


Explanation  of  Fig.  98. 

In  this,  a anil  b show  the  tendinous  part  of  the  diaphragm  or  par- 
tition between  the  chest  and  abdomen  : d,  the  kidney,  with  its  fellow 


264 


ANATOMICAL  CLASS  BOOK. 


opposite  ; /,  the  descending  aorta  ; h,  an  artery  given  off  for  the  in- 
testinal tube  ; i where  the  great  artery  divides,  to  send  a branch  to 
each  leg,  g,  the  ascending  great  vein,  conveying  blood  to  the  right 
side  of  the  heart;  c,  the  capsule,  so  called,  belonging  to  the  kidney, 
the  use  of  which  is  unknown;  n,  the  ureter,  a tube  which  conveys 
the  urine  from  the  kidney  to  the  under  side  of  the  bladder,  where  it 
terminates  : the  right  ureter  is  seen  on  that  side,  also  terminating 
in  the  bladder,  k\  in,  l,  are  arteries;  o,  is  a small  artery  which  runs 
down  on  the  bone,  into  the  pelvis. 

STOMACH. 

Just  below  the  diaphragm,  lying  nearly  horizontally 
across  the  top  of  the  abdomen,  is  the  stomach,  having  the 
shape  of  a shot-pouch, — being  large  at  the  extremity  on 
the  left  side,  and  small  where  it  reaches  the  right,  under 
the  margin  of  the  liver.  It  presents  a curve  in  front  and 
shorter  one  on  the  back  side,  where  it  embraces  the  spine. 

At  the  entrance  of  the  (esophagus,  the  food  tube  from 
the  mouth  at  the  large  end  of  the  orifice  is  called  the  car- 
diac orifice,  — because  it  was  supposed  by  the  early  anato- 
mists to  be  near  the  heart.  Through  this  the  food  en- 
ters the  stomach  ; and  where  it  makes  its  exit,  into  the  be- 
ginning of  the  intestine,  at  the  other  extremity,  the  opening 
is  the  pyloric  orifice.  A muscle  surrounds  the  neck  of 
the  stomach,  on  the  inside,  which  holds  a control  over  the 
contents,  allowing  it  to  pass  onward,  or  confining  it  within, 
according  to  its  state  of  preparation  for  digestion. 

INTESTINES. 

With  a little  variation,  the  whole  extent  of  the  intesti- 
nal tube  is  six  times  the  length  of  the  body,  except  in  in- 
fancy, when  it  averages  eight  times  the  height  of  the 
child. 

It  is  divided  into  small  and  large  intestines.  The  small 
one  is  further  divided  into,  first,  the  duodenum,  only  about 
a foot  long,  commencing  at  the  stomach : — - into  this  por- 
tion the  bile  and  pancreatic  juice  is  delivered.  Secondly, 


ANATOMICAL  CLASS  BOOIC 


265 


the  jejunum,  coiled  up  nearly  round  the  navel : and  third- 
ly, the  ileon,  the  last  part  of  this  intestine,  joining  the 
ccBcum,  or  beginning  of  the  large  tract.  Usually  the  diam- 
eter of  this  tube  is  not  far  from  one  inch. 

Secondly,  the  large  intestine  is  divided  in  the  caecum,  a 
large,  irregular  membranous  sac,  with  a valve,  that  ob- 
structs the  return  of  whatever  may  have  once  passed  it  : 
the  colon,  about  two  inches  in  diameter,  lying  near  the 
hip,  at  the  bottom  of  the  abdomen,  on  the  left  side,  but  as- 
cending in  a broad  curve  towards  the  stomach,  crosses 
the  spine,  and  dips  down  into  the  right  side,  — describing 
an  arch, — hence  this  particular  part  is  called  the  arch  of 
the  colon.  Finally,  the  rectum  is  the  last  division,  a foot 
long,  terminating  externally. 

The  inside  is  beset  with  the  sharp  folds  of  the  inner 
membrane,  in  the  form  of  shelves,  exceedingly  numerous, 
which  are  termed  valvules  conniventes.  Their  express  of- 
fice is  to  prevent  a too  rapid  exit  of  the  food,  in  its  descent, 
before  all  its  nutritious  substance  has  been  taken  by  the 
lacteals. 

Fig.  99. 

Explanation  of  Fig.  99. 

1.  The  oesophagus,  or  swallow 
perforating 

2.  The  left  opening  of  the  dia- 
phragm. 

3.  The  cardiac  orifice  of  the 
stomach. 

4.  The  small  curvature  of  the 
stomach. 

5.  The  great  curvature  of  the 
stomach. 

6.  The  fundus  of  the  stomach. 

7.  The  pyloric  orifice. 

8.  The  duodenum,  divided  into 
three  portions. 

9.  The  ascending. 

10.  The  transverse,  and 

11.  The  descending  portion. 

12.  Thejejunum,  forming  three 


97  17  4 


23 


266 


ANATOMICAL  CLASS  BOOK. 


fifths  of  the  small  intestines,  distinguished  from  the  ilium  in  being 
thicker,  more  vascular,  larger,  and  having  more  valves. 

13.  The  ilium,  forming  less  than  two  fifths  of  the  small  intestines, 
and  terminating  in  the  caecum,  having  two  valves  at  the  entrance. 

14.  The  caecum,  the  first  of  the  large  intestines  ; situated  in  the 
right,  having  attached  to  it 

15.  The  appendix  vermiformis.  The  caecum  terminating  in 

16.  The  ascending  portion  of  the  colon,  which  directs  its  course 
from  the  caecum  towards  the  stomach,  connected  to  the  right  kidney 
by  a fold  of  the  peritonaeum. 

17.  The  arch  of  the  colon,  traversing  the  abdomen  beneath  the 
stomach. 

18.  The  descending  portion  of  the  colon,  directing  its  course 
towards  the  left  region,  connected  to  the  left  kidney  by  a fold  of  the 
peritonaeum. 

19.  The  sigmoid  flexure  of  the  colon,  situated  in  the  left  iliac  re- 
gion, and  terminating  in 

20.  The  rectum. 


MESENTERY. 

A duplication  or  fold  of  the  peritonaeum,  drawn  out 
as  it  were  from  the  spine,  like  a ruffle,0, is  the  mesentery, 
on  the  border  of  which  the  intestines  adhere.  By  this 
they  are  supported  and  kept  in  place. 

Nearly  in  the  centre,  between  where  the  mesentery 
attaches  itself  to  the  spine  and  the  intestine,  are  the  me- 
senteric glands,  through  which  the  chyle  passes  in  its  way 
to  the  thoracic  duct. 

DIGESTION. 

Perhaps  no  animal  process  has  more  deeply  engaged 
the  attention  of  physiologists,  than  digestion.  The  fol- 
lowing remarks  embrace,  in  a few  words,  all  that  is  known 
upon  the  subject. 

Soon  after  the  food  has  been  admitted  into  the  stomach, 
considerably  softened  by  the  saliva  of  the  mouth  and 
throat,  the  extremely  small  arteries  spread  in  the  lining 
membrane  of  the  stomach,  throw  out  a fluid  which  is 
called  the  gastric  juice,  which,  in  addition  to  the  muscular 
action  of  the  stomach,  converts  the  whole  mass  into  a 


ANATOMICAL  CLASS  BOOK. 


267 


greyish  paste.  It  is  rolled  forward  to  the  pylorus  — the 
place  of  passage  into  the  intestine,  where  there  is  mixed 
with  it  the  bile  from  the  gall-bladder,  and  the  juice  from 
the  pancreas,  both  of  which  dilute  it  still  more.  The 
muscular  fibres  of  the  first  portion  being  strong,  it  agitates 
and  rolls  it  about,  till  it  assumes  the  appearance  of  a thick 
milky  fluid,  of  the  consistence  of  cream. 

This  part  of  the  digestive  process,  in  the  first  portion  of 
the  intestine,  is  termed  chy unification,  and  the  substance 
itself  chyme. 

By  the  peristaltic  and  vermicular  action  of  the  intestine, 
it  is  carried  onward,  inch  by  inch,  interrupted  by  the 
valves,  which  throw  it  from  side  to  side,  till  every  particle 
is  brought  into  direct  contact  with  the  mouths  of  the  lac- 
teals,  everywhere  presented.  Thus  a prodigious  extent 
of  absorbent  surface  is  presented  to  it,  through  the  entire 
course  of  nearly  thirty  feet. 

Thus,  the  further  the  chyme  advances,  the  more  closely 
and  certainly  is  its  valuable  part  taken  up  by  the  countless 
millions  of  lacteal  vessels.  They  terminate  in  the  me- 
senteric glands,  where  it  remains  a little  time,  but  for 
what  purpose  is  not  precisely  understood,  and  then,  by 
another  set  of  ducts,  the  fluid  is  conveyed  into  the  thoracic 
duct,  to  be  afterwards  carried  into  the  vein,  in  the  neck, 
to  be  mixed  with  the  blood,  and  to  become  blood. 

The  final  cause,  therefore,  of  digestion,  is  to  elaborate 
a material  for  making  blood,  from  which  the  whole  system 
is  renewed  and  sustained.  Whatever  is  useless  finally 
passes  onward  into  the  large  intestine,  which,  in  effect,  is 
a store-house,  — in  which  its  stay  is  temporary,  depending 
on  the  health,  habit  and  condition  of  the  individual. 

Three  hours  after  the  food  is  masticated,  as  a general 
rule,  it  passes  through  the  various  changes  which  have 
been  described. 

Three  coats  are  easily  shown,  in  the  walls  of  the 


263 


ANATOMICAL  CLASS  BOOK. 


stomach  and  intestines,  viz.  the  peritoneal,  the  muscular 
and  the  mucous.  The  muscular  is  a series  of  fleshy  fibres, 
fine  as  sewing  thread,  winding  round  the  cylinder;  — lon- 
gitudinal fibres  are  also  discoverable  ; hence  there  are  two 
particular  motions  in  the  intestine.  By  the  contraction  of 
the  straight  fibres,  the  intestine  is  gathered  up  in  wrinkles 
at  different  points,  through  its  whole  extent,  and  then 
elongated  again,  much  like  the  movement  of  a worm.  By 
the  contraction  of  the  others,  it  is  diminished  in  diameter 
at  different  sections  : — thus  they  are  never  at  rest,  but 
continually  moving  the  chyme  from  place  to  place.  The 
first  motion  is  the  vermicular,  and  the  second,  the  peris- 
taltic. 


ANATOMICAL  CLASS  BOOK. 


269 


THE  FLUIDS, 


OR  HYGROLOGY. 


A variety  of  fluids  are  separated  from  the  blood  by 
numerous  organs,  for  various  purposes,  which  are  divided 
into  crude , sanguineous , lymphatic , secreted  and  excremen- 
titious. 

An  example  of  a crude  fluid  is  found  in  the  chyle;  the 
sanguineous  in  the  blood ; the  lymphatic  in  the  lymphatic 
vessels;  and  the  excrernentitious , are  all  such  as  are  expelled 
from  the  system  as  useless. 

Again,  the  secreted  fluids  are  further  subdivided  into 
the  lacteal,  as  that  in  the  tubes  between  the  intestines  and 
mesenteric  glands  ; aqueous,  in  the  eye  ; mucous,  in  the 
nose  ; albuminous,  as  the  serum  of  the  blood  ; oleous,  as 
the  fat , and  bilious,  as  exemplified  in  the  bile. 

LYMPHATICS  AND  THEIR  SECRETIONS. 

Whenever  a moisture  exists,  either  externally  or  in  the 
obscure  cavities  of  the  body,  under  the  skin,  among  the 
muscles,  in  the  brain,  and  indeed  where  any  motion  is  ef- 
fected, the  lymphatics  exist  also,  though  they  are  invisible. 
They  take  up  the  vapor  or  fluid  and  carry  it  to  the  tho- 
racic cluct,  to  be  mixed  with  the  blood.  If  any  nutritious 


23* 


270 


ANATOMICAL  CLASS  BOOK. 


matter  is  unnecessarily  expended  in  any  of  these  places,  it 
is  sure  to  be  collected  again  and  returned  to  the  circulation. 

Without  these  vessels  always  on  the  alert,  fluids  would 
accumulate  beyond  the  necessities  of  the  organs  they 
were  designed  to  assist,  which  would  inevitably  abridge 
the  freedom  of  action  and  produce  disease. 

Thus,  whatever  is  superfluous  is  sent  back  to  the  blood, 
from  whence,  perhaps,  in  a majority  of  cases,  it  was  taken, 
and  if  of  no  further  value,  it  is  thrown  into  the  kidneys,  and 
a large  portion  of  it,  therefore,  is  thus  conveyed  from  the 
body,  through  the  agency  of  the  urinary  apparatus. 

FLUIDS  OF  THE  CRANIUM. 

A vapor  exhales  in  the  ventricles  of  the  brain,  secreted 
by  the  delicate  arteries,  to  prevent  an  adhesion  of  the  sides, 
and  to  keep  the  contents  of  the  head  moist. 

OF  THE  NOSTRILS. 

Part  of  the  mucous  in  these  canals,  are  the  tears  passing 
down  the  lachrymal  duct,  from  the  eyes,  adverted  to  in  the 
anatomy  of  the  eye.  Beside  this,  a congeries  of  mucipa- 
rous glands  under  the  lining  membrane,  also  mix  their 
secretions  with  them  to  preserve  the  olfactory  nerves  from 
becoming  dry,  which  would  destroy  their  sensibility. 

No  fluid  whatever  distils  from  the  brain  into  the  nose, 
as  sometimes  vulgarly  supposed.  These  are  the  only 
sources,  even  when  in  excessive  quantity,  as  when  labor- 
ing under  a severe  cold,  whence  it  arises. 

OF  THE  MOUTH. 

Under  the  tip  of  the  tongue,  the  angle  of  each  jaw,  and 
lastly,  under  the  ear,  between  the  jaw  and  neck,  are  large 


ANATOMICAL  CLASS  BOOK. 


271 


glands,  — each  secreting  a fluid  of  the  same  character,  — 
the  saliva,  in  quantity  sufficient  to  soften  the  food  for 
mastication,  and  to  keep  the  tongue,  fauces,  sides  of 
the  mouth  and  lips  moist  and  flexible.  Such  is  their  ac- 
tivity, that  several  ounces  are  ordinarily  collected  in  the 
course  of  one  meal.  Each  gland  has  a duct  leading  into 
the  mouth  : — the  motion  of  the  jaws  in  chewing  and 
swallowing  contributes  to  the  flowing  of  the  fluid. 


272 


anatomical  class  book. 


THE  SKIN. 

Above  the  muscles,  and  directly  under  the  skin,  is  a 
spongy  layer  called  cellular  substance,  the  cells  of  which 
are  filled  with  fat.  This  cellular  covering  is  enormously 
thick  in  whales,  and  denominated  the  blubber,  which 
keeps  the  animal  warm.  Above  this  is  the  true  skin,  — 
smooth  and  delicate  on  its  external  surface,  but  of  a looser 
texture  on  the  under  side,  where  it  forms  a union  with  the 
cellular  substance.  This  true  skin  is  teclmxcalhj  called 
cutis  vera.  It  is  profusely  supplied  with  blood  vessels, 
and  so  numerous  are  its  nerves,  that  the  point  of  a needle 
can  no  where  be  inserted  without  wounding  one  of  them. 

As  all  the  nerves  finally  run  towards  the  surface  of 
the  body,  it  has  led  some  to  the  opinion  that  the  true  skin 
was  a tissue  of  nerves  and  vessels,  so  intimately  inter- 
woven as  to  constitute  a highly  sensitive  envelope  for  the 
body.  The  color  of  the  true  skin  is  nearly  the  same  in 
all  races  of  men,  — being  as  white  in  the  negro  as  in  the 
European. 

BETA  MUCOSUM. 

There  is  spread  over  the  true  skin  an  extremely  thin 
layer  of  paint,  of  the  consistence  of  thin  size,  — which 
has  received  the  name  of  reta  mucosum,  and  on  this  wholly 
and  entirely  depends  the  color  or  complexion  of  the  indi- 


ANATOMICAL  CLASS  BOOK. 


273 


vidual.  In  the  negro,  this  mucous  paste  is  jet  black  ; in 
the  Indian  copper  colored  ; in  the  Spaniard  yellowish, 
but  white  in  the  white  variety  of  our  species.  This  pig- 
ment is  constantly  flowing  out  upon  the  skin,  to  defend  its 
irritable  surface  against  the  combined  influence  of  the  air, 
light  and  heat.  These  agents,  however,  exert  an  action 
upon  the  mucous  coloring,  which  dries,  becomes  hard  and 
insensible,  and  is  continually  wearing  off,  and  as  con- 
stantly renewed. 

SCARF-SKIN. 

A familiar  example  of  the  scarf-skin,  the  exterior  coat 
of  all,  is  observable  in  blisters.  It  is  totally  insensible, 
rough  and  by  no  means  of  a uniform  thickness.  In  the 
palms  of  the  hands  and  soles  of  the  feet,  it  becomes  prodi- 
giously thickened,  to  defend  the  tender  parts  below.  This 
scarf-skin  is  constantly  wearing  off,  and  as  constantly  re- 
newed, and  hence  it  is  inferred  that  it  is  really  nothing 
more  than  the  rete  mucosum,  thrown  off  by  the  action  of 
the  excretory  vessels. 

The  query  may  arise,  why,  if  this  is  the  case,  are  not 
the  palms  of  the  negro’s  hands  perfectly  black?  They  would 
be  so,  if  the  scarf-skin  in  them  had  not  lost  its  vitality. 
When  the  negro  has  suffered  from  a severe  burn,  the 
mouths  of  the  ducts,  which  poured  out  the  coloring  matter, 
are  sealed  up  by  the  subsequent  inflammation,  so  that  no 
more  paint  is  thrown  out,  — • and  the  scar  remains  white. 
The  reason  is  plain,  — the  true  skin,  which  is  white,  is 
no  longer  obscured  by  the  black  pigment. 

Rouge,  pearl  powder,  cream  of  almonds,  milk  of  roses, 
cologne,  spirit  of  wine,  and,  indeed,  the  endless  catalogue 
of  cosmetics,  which  are  sold  in  the  shops  with  the  ostensi- 
ble object  of  beautifying  the  skin,  are  abominable  impo- 
sitions, which  ought  to  be  interdicted  by  a strict  police 
regulation,  till  the  happy  period  arrives  when  common 


274 


ANATOMICAL  CLASS  BOOK. 


sense  is  more  frequently  exercised  on  the  subject  of  per- 
sonal appearance.  The  skin  cannot  be  made  permanently 
whiter,  — nor  can  the  hair  be  stained  without  injuring  it; 
— a roseate  tint  cannot  be  given  to  the  cheek  by  any  pre- 
paration, that  will  be  abiding.  All  this  class  of  pretended 
beautifying  articles  positively  injure  the  skin,  leaving  it 
rougher  ; and  in  old  age,  in  consequence  of  their  habitual 
application,  the  face  is  more  thickly  wrinkled,  and  the 
complexion  assumes  the  hard  dead  color  of  bronze.  Still 
worse,  the  pores  are  deranged  in  their  functions,  and  dis- 
ease may  be  induced  by  the  absorption  of  some  of  the 
ingredients  of  those  noxious  importations,  which  were 
never  good  for  any  thing  but  to  fill  the  manufacturer’s 
purse  at  the  expense  of  those  who  are  willing  to  be  the 
dupes  of  their  own  folly.  Cold  water  is  truly  a cosmetic  — 
and  should  be  used  exclusively. 

The  physiology  of  the  nails,  which  are  supposed  to  be  a 
production  of  the  scarf-skin, — is  not  well  understood.  — 
Writers  have  not  given  a satisfactory  explanation  of  their 
origin  or  growth. 

With  respect  to  the  hair,  its  growth  bears  a striking 
analogy  to  vegetables,  — inasmuch  as  it  rises  from  a bul- 
bous root,  imbedded  in  the  skin,  into  which  a gelatinous 
fluid  is  secreted.  It  would  be  entirely  unnecessary  to  de- 
tail the  opinions  of  authors  on  the  subject,  or  to  be  very 
particular  in  relating  our  own.  Hereafter,  the  physiology 
of  the  skin,  nails  and  hair  will  become  the  topic  of  a dis- 
tinct essay,  — with  reference  to  the  abuses  of  the  toilet. 


ANATOMICAL  CLASS  BOOK. 


275 


QUESTIONS. 


What  is  Adenology  ? 

What  is  the  use  of  glands  ? 

Where  is  the  diaphragm  ? 

What  organs  are  contained  within  the  chest? 

What  is  the  object  of  respiration  ? 

How  do  insects  breathe  ? 

Is  breathing  involuntary  in  reptiles  ? 

Where  is  the  organ  of  voice  located  ? 

How  is  the  larynx  formed? 

Where  are  the  vocal  cords  found  ? 

What  musical  instrument  does  the  larynx  resemble  ? 
What  is  the  object  of  the  thoracic  duct? 

How  is  the  abdomen  bounded  ? 

What  is  the  omentum? 

Where  is  the  liver  placed  ? 

Where  is  the  gall  bladder  found  ? 

Is  the  use  of  the  spleen  known  ? 

What  is  the  function  of  the  pancreas  ? 

Where  are  the  kidneys  lodged? 

What  is  the  shape  of  the  stomach  ? 

How  is  digestion  performed  ? 

What  is  chymification  ? 

What  is  the  use  of  the  saliva? 

How  many  coats  has  the  stomach  ? 

What  is  hygrology  ? 


276 


ANATOMICAL  CLASS  BOOK. 


What  are  the  lymphatics  ? 

Is  any  fluid  found  in  the  brain  ? 

What  organs  supply  fluid  to  the  mouth  ? 

On  what  does  the  color  of  the  body  depend  ? 

What  do  you  understand  by  the  true  skin  ? 

Where  is  the  rete  mucosum  secreted  ? 

Why  is  a negro  black  ? 

What  is  the  scarf-skin  ? 

How  is  the  hair  produced  P 

Are  the  nails  a production  of  the  skin  ? 

Where  is  the  sense  of  touch  most  perfect  P 
Why  are  there  valves  in  the  intestinal  tube? 

Where  is  the  gastric  juice  formed? 

Where  are  the  lacteal  vessels  ? 

What  becomes  of  the  nutritious  part  of  the  food  ? 

Are  there  openings  to  the  stomach  ? 

What  is  the  use  of  bile  or  gall  ? 

Of  what  service  is  the  liver  ? 

How  are  the  intestines  kept  in  place  ? 

Where  is  the  cellular  membrane  ? 

Are  the  lungs  separated  in  the  chest  ? 

How  are  the  tones  of  the  voic'e  varied  ? 

What  is  the  glottis  ? 

What  prevents  food  from  falling  into  the  wind-pipe  ? 
What  is  the  epiglottis  ? 

By  what  organs  is  the  voice  modulated? 


Anatomy,  . . . 

Anatomy,  comparative, 
Angiology,  . 
Adenology, 

Arm  bones, 

Antagonists,  of  muscles. 
Absorbents, 

Auricles, 

Artery,  coronary, 
Alveus  communis, 
Arteries  of  the  brain, 
Arteries  of  the  face, 
Arteries  of  the  thigh, 
Artery  of  the  arm, 

Air  tubes, 

Auditory  nerve. 

Aorta,  . 

Aqueous  humor, 
Abdomen,  '. 
Bursology, 

Bones  in  the  Skeleton, 
Bones  in  the  skull, 
Bones  in  the  face, 

Bone  of  the  tongue, 
Bones  of  the  trunk, 
Bones  of  the  hand. 
Bones  of  the  leg,  . 
Bones  of  the  foot, 

Bones  of  the  nose, 
Breast  bone, 

Bones  of  the  loins, 
Busks, 

Blood  in  muscles, 

24 


Page . 

Blood,  eirculation  of,  . 115 

Brain,  insensible,  . 158 

Brain  of  worms,  . . 160 

Brain,  structure  of,  . 156 

Breathing  of  fishes,  . 247 

Breathing  of  shell  fish,  248 

Both  eyes  see  but  one  object,  232 
Cylindrical  bones,  . 2 

Clavicle,  ...  5 

Connexion  of  bones,  . 9 

Cheek  bones,  ...  16 

Carpus,  ...  28 

Corsets,  ....  40 

Cutting  teeth,  . . 41 

Chewing  tobacco,  . . 42 

Catalogue  of  muscles,  . 59 

Cavities  of  the  heart,  . 122 

Compound  lever,  . 191 

Carotid  artery,  . . 134 

Capillaries.  . . . 140 

Contraction  of  arteries,  . 142 

Circulation  of  the  blood,  145 

Crassamentum,  . . 149 

Color  of  the  blood,  . 149 

Cerebrum,  . . . 153 

Coverings  of  the  brain,  155 

Caterpillar,  . . . 246 

Clam,  ....  248 

Cause  of  voice,  . . 257 

Cosmetics,  . . . 273 

Cochlea,  . . . 196 

Coats  of  the  eye,  . . 209 

Ciliary  processes,  . . 213 


Page. 

1 

2 

2 

2 

26 

57 

97 

126 

131 

192 

137 

136 

139 

141 

245 

197 

130 

216 

258 

2 

3 

4 

4 

5 

5 

6 

6 

6 

16 

22 

23 

40 

58 


278 


INDEX. 


Choroides, 

Page. 

210 

Cornea,  . 

. 211 

Cataract, 

219 

Convex  spectacles, 

. 228 

Concave  glasses,  . 

230 

Cross-eye, 

Distortion  of  the  bones, 

. 233 

37 

Double  heart, 

Double  heart,  plan  of  . 

121 

125 

Diastole  of  the  heart, 

. 130 

Dorsal  nerves, 

166 

Drum  of  the  ear, 

. 182 

Dr  Darwin’s  opinion  of 

deaf- 

ness, 

192 

Diagram  of  the  heart, 

. 147 

Dura  mater, 

155 

Diaphragm, 

. 243 

Deafness,  partial,  . 

202 

Deafness,  permanent, 

. 202 

Epiphises, 

3 

Enamel  of  the  teeth, 

41 

Extensors  of  the  toes,  . 

106 

Ear, 

. 175 

External  ear, 

176 

Ear  wax, 
Eustachian  tube, 

180 

185 

Error  loci, 

. 150 

Ear,  diseases  of, 

201 

Ear  ach, 

. 201 

Eye,  . . 

205 

Flat  bones, 

2 

Finger  bones, 

29 

Female  skeleton, 

36 

Friction,  prevention  of, 

57 

Face,  muscles  of, 

60 

Fascia  of  the  arm, 

91 

Fluids, 

115 

Frog’s  heart, 

. 126 

Force  of  the  auricle, 

129 

Food-pipe, 

Growth  of  the  bones, 

. 257 

. 35 

Greater  circulation. 

124 

Glands  of  the  ear  tube. 

. 181 

Gall-bladder, 

260 

Globe  of  the  eye, 

. 206 

Hygrology,  . 

2 

Hip  bones, 

24 

Hand,  bones  of, 

28 

Heart  of  vermin, 

. 119 

Heart  of  fishes, 

119 

Heart,  shape  of, 

Page. 

122 

Heart-case, 

132 

Heart-case,  use  of,  . 
Hearing  of  insects, 

132 

176 

Hydrocanthiri, 
Humors  of  the  eye,  . 

246 

216 

Hair,  .... 

272 

Instep,  .... 

32 

Involuntary  muscles, 

53 

Irritability  of  muscles, 

56 

Influence  of  the  nerves, 

59 

Imposition  in  bone  setting, 

107 

Internal  cords  of  the  heart, 

126 

Intercostal  nerves, 

157 

Involuntary  nerves, 

163 

Intestines, 

263 

Image  inverted  in  the  eye, 

231 

Iris,  .... 

212 

Joints, 

114 

Jugular  vein,  . 

139 

Knee,  security  of, 

103 

Kidneys, 

261 

Lower  jaw, 
Ligaments, 

17 

45 

Ligaments  of  the  knee, 

46 

Ligaments  of  the  hand. 

47 

Ligaments  of  the  foot,  . 

48 

Lumbar  abscess, 

75 

Lacing, 

77 

Latissimus  muscle,  . 

82 

Lesser  circulation, 

124 

Left  heart  filled  at  death, 

124 

Little  bones  of  the  ear, 

188 

Little  brain, 

Lobes  of  the  brain,  . 

153 

154 

Lungs, 

243 

Lizards,  aquatic, 

249 

Lungs  of  reptiles, 

249 

Lungs  of  frogs, 

250 

Language, 

253 

Larynx, 

254 

Liver,  .... 

258 

Lens,  crystaline,  . 

218 

Myology, 

2 

Metacarpus, 

28 

Muscles,  physiology  of, 

50 

Muscles,  number  of, 

51 

Muscles,  shape  of, 

52 

Muscles,  two  orders  of, 

55 

Muscles  never  weary, 

55 

INDEX. 


279 


Page. 

Muscles  of  the  ear,  . 64 

Pleura, 

Page. 

148 

Muscles  of  the  neck, 

66 

Pancreas, 

260 

Muscles  of  the  jaws. 

66 

Pupils  of  albinos  red, 

234 

Muscles  of  the  throat, 

70 

Ribs, 

21 

Muscles  of  the  abdomen, 

72 

Roots  of  teeth. 

41 

Muscles  of  the  pelvis, 

74 

Round  window, 

186 

Muscles  of  the  chest, 

76 

Rete  mucosum, 

270 

Muscles  of  the  back, 

80 

Syndesmology, 

2 

Muscles  of  the  arm, 
Muscles  of  the  thigh, 

86 

Splanchnology, 

2 

96 

Skeleton, 

3 

Muscles  of  the  foot, 

104 

Sesamoid  bones, 

3 

Motion  of  the  heart. 

123 

Structure  of  bones,  . 

9 

Mechanism  of  the  nerves. 

158 

Seivebone, 

13 

Musical  ear, 

200 

Sutures  of  the  head, 

13 

Membrana  Nictitans, 

226 

Spine, 

18 

Names  of  muscles, 

101 

Shoulder, 

25 

Nerves  of  the  thigh, 

102 

Small  waist, 

38 

Notions  of  the  ancients, 

117 

Sugar,  effects  of  on  teeth 

42 

Nerves  of  the  heart, 

131 

Suspended  animation. 

58 

Nerves, 

Nerves  of  the  foot. 

153 

Strength  of  the  right 

arm, 

87 

158 

Supinator  muscles,  . 

92 

Nerves  of  the  arm, 

168 

Sole  of  the  foot, 

109 

Nerves  accompany  arteries, 

163 

Single  heart. 

120 

Nine  pair  of  nerves, 

164 

Spinal  marrow, 

157 

Nerves  of  the  face, 

168 

Sympathetic  nerve, 

173 

Nerves  of  the  eye, 

169 

Senses, 

175 

Nerve  of  the  tongue, 

171 

Semicircular  canal, 

187 

Nymphs  of  gnats, 

246 

Stapes, 

189 

Nerves  of  a perch. 

247 

Spiracula, 

245 

Nearsightedness, 

229 

Spallanzani, 

244 

Neuts, 

250 

Spleen, 

260 

Osteology, 

2 

Stomach, 

263 

Os  frontis. 

10 

Seeing  in  the  dark. 

235 

Occipital  bone, 

12 

Seeing  in  water, 

235 

Os  hyoides,  . . . 

18 

Smelling, 

240 

Olfactory  nerves, 

167 

Socket  of  the  eye, 

206 

Optic  nerves. 

167 

Sclerotica, 

209 

Oval  window, 

186 

Scarf  skin,  . 

271 

Oyster,  how  it  lives  on  land, 

248 

Teeth,  number  of, 

4 

Omentum, 

258 

Temporal  bone, 

12 

Optic  nerve, 

222 

Tear  bones, 

17 

Processes, 

3 

Tibiae, 

31 

Palate  bones, 

17 

Thigh  bone, 

31 

Periosteum, 

34 

Teeth, 

41 

Practice  of  muscles, 

54 

Tendons, 

57 

Pronator  muscles, 

92 

Two  sets  of  blood  vessels. 

123 

Power  of  the  left  heart, 

124 

Tube  of  the  ear,  . 

179 

Position  of  the  heart. 

133 

Tympanum, 

184 

Primative  artery. 

135 

Tasting, 

141 

Pia  mater. 

156 

Thyroid  Cartilage, 

255 

280 


INDEX. 


Thymus  gland. 

Page. 

257 

Thoracic  duct, 

. 258 

The  eye  adapts  itself  to  distan- 

ces, 

. 237 

Tears, 

227 

True  skin, 

. 270 

Upper  jaw  bones, 

16 

Vertebrae, 

19 

Voluntary  muscles, 

53 

Ventricles  of  the  heart, 

. 126 

Vena  cava, 

127 

Valves  of  the  heart, 

. 130 

Vestibule, 

. 191 

Veins,  . . , 

143 

Veins  of  the  leg, 

Page. 
. 144 

Vitality  of  the  blood, 

148 

Viscera  of  the  chest, 

. 142 

Voluntary  respiration,  . 

244 

Vermin, 

Voice  of  animals, 

. 245 

251 

Voice  of  man, 

. 253 

Vocal  strings, 

256 

Valves  of  the  intestines, 

. 264 

Wall  bones,  . 

12 

Wedge  bone,  . 

12 

Wrist,  bones  of. 

27 

Wisdom  teeth, 

41 

Warm  blooded  animals, 

120 

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